Hexarelin: The Definitive Guide

What is hexarelin?

Hexarelin is a lab-made peptide, a chain of six amino acids, that makes the pituitary gland release a burst of growth hormone. People discuss it for muscle, strength, body composition and heart health, usually in short blocks because its effect fades with repeated use. We found no approval as a medicine in any country we checked. [1], [2], [3], [12]

It works by copying the action of ghrelin, a hormone made mainly in the stomach, at the ghrelin receptor (also called GHS-R1a). That receptor is one of the switches that tells the pituitary gland, a pea-sized gland at the base of the brain, to release growth hormone. Because hexarelin makes the body release its own hormone rather than supplying it, it is called a growth hormone secretagogue. It belongs to the family known as GHRPs (growth-hormone-releasing peptides), with GHRP-2 and GHRP-6. [4], [5], [6]

The name reflects its six amino acids ("hexa" means six). Its official international name is examorelin, the name used on the World Anti-Doping Agency's list, and it was developed under the codes EP-23905 and MF-6003. It was made by modifying GHRP-6, and two of its six building blocks are mirror-image (D-amino acid) forms that do not occur in the body's own proteins. [1], [7], [8], [6]

Hexarelin was studied in people mainly in the 1990s, as a possible growth-hormone test and treatment. It never reached approval, and we found no clinical trial registered for it in the US, European, WHO, UK or Japanese registries. It remains investigational: we found no regulator that has approved it, and there is no approved dose. [9], [10], [11], [12]

Typical Hexarelin Protocols

The most common pattern in the reviewed sources is 100–200 mcg per injection, given once or twice a day (some sources go to three times), on an empty stomach, in blocks of about 4–8 weeks followed by at least 4 weeks off. Shorter blocks are more common for hexarelin than for related peptides, because sources expect its effect to fade. [13], [14], [15], [16], [17], [18], [19], [20], [21]

Titration Changing the amount in steps

The usual approach starts at 100 mcg once a day and, if it is tolerated, moves to 200 mcg once or twice a day. A few step-up schedules continue to 300 mcg twice a day. Others keep one fixed amount for the whole block. No source reports a tested reason for any particular step. [22], [23], [24], [17]

Breaks and cycles

Most sources run hexarelin for 4 weeks, or at most 8, and then stop for 4 weeks or longer. Some add two days off each week, a pattern written as 5 days on, 2 off. The one relevant human finding: after 16 weeks of twice-daily injections, the growth-hormone response was back to its starting level 4 weeks after stopping. [14], [13], [25], [24], [26], [3]

Read the units: mcg means micrograms; 1 mg equals 1,000 mcg. The amounts are for each injection, and the daily total is shown separately. The human studies gave hexarelin by body weight instead: 1.5 mcg per kilogram is about 105 mcg for a 70 kg adult and 120 mcg at 80 kg, so the lower website amounts sit close to the doses that were studied. [3], [27]

Each row is a complete schedule as its source published it, and low, mid and high are alternatives, not steps to move through. These schedules come from protocol websites rather than clinical trials; the only injection schedule tested over weeks in adults was 1.5 mcg per kilogram twice a day for 16 weeks, in 12 healthy older adults. [13], [3], [28]

Before relying on any row: no fixed-microgram schedule in these tables has been tested in people. Repeated injections above about 1.5 mcg per kilogram (roughly 105–120 mcg for most adults), and three injections a day for more than one day, have no human data at all. Single injected test doses raised prolactin, ACTH and cortisol for a few hours, and one small study found less deep sleep after night-time doses. There are no human data in pregnancy or breastfeeding (in mice, daily injections reduced ovulation), and the studies in children were supervised medical research that does not support use under 18. People with diabetes, a history of cancer, or a pituitary or adrenal condition have extra reason for caution. No approved product exists, so the strength and sterility of a vial depend entirely on its maker. Hexarelin is banned in sport at all times. [29], [30], [31], [32], [33], [8] Full risks and who should be cautious.

What are the usual hexarelin and CJC-1295 blend amounts?

Hexarelin is often combined with CJC-1295 without DAC, also sold as Mod GRF 1-29, a lab-made version of the brain's growth-hormone-releasing hormone (GHRH). The two act on different switches in the pituitary. In healthy men, hexarelin given into a vein with GHRH(1-29), the short form of the natural hormone that is also sold as sermorelin, released more growth hormone than the two alone added together; no study has tested hexarelin with CJC-1295 itself. The amounts below are per peptide. [38], [18]

Two other protocol pages give the same 100 mcg plus 100 mcg pairing twice or up to three times a day without a separate course length, and another pairs 100–200 mcg of hexarelin with 100 mcg of CJC-1295 once at bedtime, also without a course length for the blend. In community education groups, one course pairs 200 mcg of hexarelin with 100 mcg of CJC-1295 without DAC twice a day for 4–6 weeks before a competition. No study has tested hexarelin with CJC-1295 itself. The human combination studies used the natural hormone's short form, gave it once or twice in a day, and found that the extra release was lost when the pair was given again one or two hours later. [17], [40], [24], [38]

What is hexarelin commonly used for?

People look into hexarelin because they want more growth hormone, and they hope that more growth hormone will bring more muscle and strength, less body fat, faster recovery or, more recently, protection for the heart. Protocol pages file it under muscle growth and call it the strongest peptide of its kind. Some clinics prescribe it, one handing patients a sheet for a ready-mixed compounded solution, and in community education groups it is often described as an advanced, short-term tool, for example before a competition. [13], [44], [26], [15], [45], [46]

The research gives a narrower picture. What has been measured in people is a strong, short growth-hormone pulse after each dose and a brief rise in the heart's pumping after one intravenous dose. The one 16-week adult study found no change in muscle, fat, bone density or IGF-1. No controlled trial has tested any of the popular uses (muscle, fat loss, recovery or long-term heart protection), and the heart-protection findings over weeks come from animal studies. [2], [47], [3], [11]

Doserly

Where do the popular hexarelin claims come from?

Mixed: human hormone studies, animal studies, websites

“The strongest GHRP”

One small head-to-head study

In young adults, GHRP-2 released a similar amount of growth hormone; natural ghrelin released more.

“Builds muscle and burns fat”

16 weeks, 12 older adults

Twice-daily injections left lean mass, body fat, bone density and IGF-1 unchanged.

“Improves sleep”

7 young adults, night doses

Deep (slow-wave) sleep went down, not up.

“Half-life of 55 minutes”

A misread number

55 minutes was growth hormone's half-life; hexarelin itself was not measured in people.

“Protects the heart”

Single doses in people; weeks only in animals

One IV dose briefly raised pumping; longer protection only in rats and mice, with some negative results.

“Tolerance becomes permanent”

16 weeks, 12 older adults

The growth-hormone response faded by about 45% and was back to normal 4 weeks after stopping.

Six website claims checked against the cited human, animal and laboratory studies.

The growth-hormone pulse is well measured in people; the muscle, sleep, heart and permanence claims rest on single doses, animals or a misread number.

Raising growth hormone and IGF-1

This is the effect hexarelin is known for, and it is well measured. After one intravenous dose, growth hormone peaked at about 30 minutes and was back to baseline within 4 hours, and 1 mcg per kilogram released about twice as much as the same dose of GHRH, the brain's own releasing hormone. Subcutaneous injections worked too, and a larger dose gave a larger pulse. [34], [2]

IGF-1 (insulin-like growth factor 1) is a hormone made mainly by the liver in response to growth hormone, and the blood test people use to check for a change. Here the results are less impressive. Over 16 weeks of twice-daily injections in older adults, IGF-1 did not change significantly, and one day of two or three injections did not change it either. A 15-day oral course raised IGF-1 slightly, and in short children given nasal hexarelin for months IGF-1 rose from 10.4 to 14.1 nmol/L. [3], [27], [36], [10]

Age matters. In older men, a single dose released less than half the growth hormone it released in young men, although prolactin and cortisol responses were the same at every age. The pituitary also has to be able to respond: hexarelin released no growth hormone in people with pituitary damage or with a faulty GHRH receptor. [48], [35], [49], [50]

Muscle, strength and body composition

No trial has tested hexarelin for muscle or strength. The one adult study that measured body composition, 16 weeks of twice-daily injections in 12 healthy older adults, found no significant change in lean body mass, total body fat or bone density. The authors concluded that the effect of that schedule on the growth-hormone system "seems to be minimal". [3]

Personal accounts range from a stronger, "fuller" look to no change at all, and nearly all involve other peptides taken at the same time. [51], [52], [53] See what people report.

Fat loss

No human study has tested hexarelin for fat loss; the one study that measured body fat found no change over 16 weeks. The fat-related findings are from cells and animals: in fat cells grown in a dish, hexarelin reduced the stored fat through a receptor called CD36, and in insulin-resistant mice it lowered fat mass and blood fats over 12 days. In genetically obese mice, a continuous low-dose infusion for 3–4 weeks reduced belly fat and improved insulin sensitivity but did not improve how they handled a sugar load. [3], [54], [55], [56] Explore the animal research.

Heart health

This is the most distinctive part of hexarelin's research record. In five small human reports, one intravenous dose raised the heart's pumping strength for up to about 90 minutes, but not in people with dilated cardiomyopathy (an enlarged, weakened heart). Growth hormone given directly did not do this, which suggests hexarelin acts on the heart itself. [47], [57], [58], [59], [60]

Longer-term protection comes from animals: rats and mice given hexarelin for days to weeks after a heart attack or in heart failure had better heart function, and in one mouse study fewer died. Not every animal result is positive: a single oral dose in mice did not change survival, and in rats with high blood pressure in the lungs, repeated hexarelin given beforehand did not prevent the right side of the heart from thickening. No human study has given hexarelin for more than one dose to protect the heart, and none has measured heart attacks, heart failure or survival. [61], [62], [63], [64], [65] See the human heart studies.

Sleep

Several protocol pages list deeper sleep as an early benefit. The only sleep study points the other way: in seven healthy young adults, night-time doses reduced the deepest stage of sleep, and personal accounts are split between very long sleep and insomnia. [22], [24], [18], [31], [43], [66] See the sleep study.

Recovery and injuries

We found no study of hexarelin for tendon, ligament, muscle or wound healing in people or animals. On public forums, one person said a doctor had suggested it for tendinitis, with no outcome posted. Another credited it with faster healing and better knees without saying what else they took or measuring anything, and a third ran it with TB-500 and ipamorelin during injury rehabilitation without reporting a healing result. The nearest findings are a rat study in which it prevented bone loss after the testes were removed and a rat study of muscle damage caused by chemotherapy. [67], [68], [69], [70], [71]

Growth in children and testing for growth-hormone deficiency

These were the medical uses researchers actually tested in the 1990s: nasal hexarelin raised growth speed in short children, and a single intravenous dose worked as a screening test for growth-hormone deficiency. Neither was approved, and they are research history, not reasons for adults to use it today. [10], [9] More on these studies.

Where do hexarelin protocols differ?

Is the number for one injection or the whole day?

Check which one a source means before comparing numbers. Most pages give an amount per injection, so 200 mcg three times daily is 600 mcg a day. Others give a daily total: one page's cost table lists "400–600 mcg total" for two or three injections, and two near-identical pages say 200–300 mcg is the daily intake, split into doses of about 100 mcg. One card in community education groups gives the same 200–300 mcg range without saying which it means. Read as per injection it is among the highest amounts in circulation; read as per day, as those pages state it, it is about 100 mcg per injection. [72], [26], [18], [73], [74]

Once, twice or three times a day?

All three appear. Sources that favour several injections a day aim to create several separate growth-hormone pulses; two documents give 100 mcg three times a day, one of them for 20 weeks. Others recommend a single daily injection "due to desensitization risk", and one US clinic's patient sheet gives 100–200 mcg every morning, Monday to Friday. [14], [13], [40], [41], [75], [76], [46]

One small human study tested this directly, for a single day. In six healthy young men, two injections of 1.5 mcg per kilogram raised the day's total growth-hormone release just as much as three did. The third injection added nothing, and the earlier doses blunted the response to a later test dose. No study has compared once-daily with twice-daily use over weeks. [27]

Timing varies as well: morning on an empty stomach, straight after training, in the evening, or before bed to line up with the body's own night-time release. Growth-hormone peaks after a dose were the same in the morning and during sleep, but night-time doses in another small study reduced deep sleep, which is why some educators in community education groups move hexarelin to the morning. [77], [41], [18], [78], [31]

Do sources start low?

Many do, most often at 100 mcg once a day for the first week or two. A few step-up schedules then climb to 200 mcg twice a day or 300 mcg twice a day. At the other extreme, one page suggests a few doses a week, or a single 200 mcg dose every 10–14 days. [22], [24], [79]

Some pages convert the human study doses by body weight: 1–2 mcg per kilogram becomes 80–160 mcg for an 80 kg person. That arithmetic is correct, but most of those per-kilogram doses were single intravenous tests, not repeated injections. [80], [81], [34]

How long, and how long off?

Course lengths range widely:

• 2–4 weeks on several pages, framed as a way to avoid the fading response, down to 2 weeks on and 2 off. [23], [79], [82]
• 4 weeks on, 4 weeks off, the most repeated rule. [14], [13], [18], [19]
• 4–8 weeks on, with breaks of 2–8 weeks. [26], [25], [17]
• 8–12 weeks or longer: "8–16 weeks with mandatory 4–8 week breaks" on one page, 12–16 weeks with 25–30 days off on two copied pages, and 20 weeks of 100 mcg three times a day in one dosing guide. One page says the effect fades within 1–2 weeks yet proposes 8–12 weeks of use. [39], [81], [83], [73], [75], [84]

Community education groups show the same spread, from 4–6 weeks on with 12 or more weeks off to one card allowing 6–16 weeks. In practice, members who describe their own use run about 4 weeks and then take a month off everything that raises growth hormone.

Weekends off are another variation. One forum user who felt the effect weaken after 10 straight days switched to 5 days on and 2 off, and a clinic sheet schedules weekday mornings only. [85], [46]

The only human data show the fading is real, partial and reversible: the response was about 31% lower after one week and 45% lower at 16 weeks, and back to normal 4 weeks after stopping. No study has compared course lengths or tested whether weekends off slow the fading. [3] See the 16-week results.

Does it have to be taken on an empty stomach?

Nearly every source says so, usually at least 2 hours after eating and 30–45 minutes before the next meal. Here there is some human evidence: in 12 healthy adults, eating a meal first cut the growth-hormone response to hexarelin by about 41%, although the response was still larger than the body's own releasing hormone produced when fasting. [72], [13], [86]

Is there a "ceiling dose"?

Several pages describe a "well-established" ceiling of about 200 mcg per injection, above which more hexarelin adds nothing. What the studies actually showed is that the growth-hormone response to a single intravenous dose levelled off at about 1–2 mcg per kilogram, roughly 70–140 mcg at 70 kg. No study has found a ceiling for subcutaneous injections. Prolactin also levelled off at 1 mcg per kilogram, while cortisol rose in a step from 0.5 mcg per kilogram. [72], [17], [34], [29]

A few pages go well above the usual range: 300 mcg two or three times a day, and 400 mcg twice a day in one "high" tier. No human data exist anywhere near these amounts given repeatedly. [22], [24], [17]

Should it be combined with CJC-1295, CJC-1295 with DAC or ipamorelin?

• With a GHRH peptide (CJC-1295 without DAC, sermorelin). This is the pairing most sources describe, and the only one with a human rationale: a very low dose of hexarelin given with GHRH released a large amount of growth hormone with a moderate rise in prolactin and no rise in cortisol. The extra effect of the pair was lost when both were given again one or two hours later. These studies used the natural hormone's short form, not CJC-1295. [29], [38], [24]
• With CJC-1295 with DAC, a long-acting version given once or twice a week. One page calls hexarelin at 100–150 mcg twice a day plus 2–3 mg of CJC-1295 with DAC twice weekly "one of the most studied growth hormone optimization protocols". We found no study of that combination. [83]
• With ipamorelin or another GHRP. Most sources, and educators in community education groups, say never to combine two peptides that act on the same receptor, because they compete for it rather than adding up. Yet the same page that recommends the DAC stack lists ipamorelin as a common partner, and one contest-preparation plan in a community course layers hexarelin on GHRP-2. In people, ghrelin and hexarelin given together released no more growth hormone than ghrelin alone. [24], [83], [4]

Doserly's guides cover CJC-1295, ipamorelin, GHRP-2 and the CJC-1295 and ipamorelin blend.

Why do websites disagree about potency, half-life and absorption?

Because several of them repeat numbers that the studies do not support:

• "The strongest GHRP." In the one head-to-head human comparison, GHRP-2 released the same amount of growth hormone, and natural ghrelin released more. [6], [4]
• "Half-life of 30–55 minutes" (or 70 minutes, or 1.5–2 hours). The 55 minutes comes from a 1994 study where it described growth hormone leaving the blood, not hexarelin. No human half-life for hexarelin has been published. [40], [83], [87], [88], [34]
• "95–98% subcutaneous bioavailability." The only human estimate is 77%, worked out from the growth-hormone response rather than blood levels of the drug. [83], [2]
• "No appetite or cortisol increase." Both were measured in people after single doses. [77], [89], [30]
• "Never tested in humans." One page says so, but dozens of small human studies were published between 1994 and 2004. [73], [34], [3]
• Trials that cannot be found. One page cites a 40-person "Phase II" trial and a 30-person 2004 trial; we found neither in PubMed or ClinicalTrials.gov. [87], [11]

How do micrograms convert to syringe units?

A U-100 insulin syringe has 100 units per millilitre, so units measure volume. How much hexarelin each unit holds depends on how much liquid was added to the vial.

For example, a 5 mg vial (5,000 mcg) mixed into 2 mL gives 2,500 mcg per mL, or 25 mcg per unit. So 100 mcg is 4 units and 200 mcg is 8 units. Mixed into 2.5 mL instead, the same vial gives 2,000 mcg per mL, so 10 units hold 200 mcg. [13], [15], [17]

Ready-mixed products change the arithmetic. One clinic's compounded solution holds 1 mg per mL, so each unit holds 10 mcg and 100–200 mcg is 10–20 units, more than twice the units of the vial example above for the same amount. Units copied from one product can never be carried over to another. [46]

Labels and course cards contain slips, such as 300 mcg written as 0.5 mg (it is 0.3 mg). Doserly's reconstitution calculator works through the arithmetic step by step. It assumes the vial holds what its label says; it cannot check a product's strength, purity or sterility.

What happens when you stop hexarelin?

The growth-hormone response comes back. In the 16-week adult study, the response was back to its starting level 4 weeks after the last injection, and so was the cortisol response to a morning test dose, which had fallen by about a fifth. [3], [28], [94]

Recovery was only partial in a study of children. In seven short children given nasal hexarelin for 6–10 months, the response to an intravenous test dose fell by more than three-quarters, and 3 months after stopping it had recovered to only about half of its starting level. In old dogs given hexarelin in three separate blocks, the response rose and then dropped back to its starting level during each block, and each break restored it. [37], [95]

No study has looked specifically for withdrawal effects or a rebound after hexarelin, and none have been described. That is missing data, not proof that none exist. The claim, repeated in some community education courses, that overuse makes the tolerance permanent or leaves growth hormone lower than before is not supported by the human studies.

In community education groups, the usual plan is a month off everything that raises growth hormone after a hexarelin block, and one course notes that stopping at once is fine after short courses. Neither has been tested. See the 16-week figure.

Does hexarelin work the same by injection, nasal spray or by mouth?

No. Hexarelin was tested in people by four routes, and the route changes how much of it acts. In 12 healthy young adults, researchers compared the growth-hormone response after intravenous, subcutaneous, intranasal (sprayed into the nose) and oral (swallowed) doses. Every route released growth hormone, but the doses needed were very different. [2]

Compared with an intravenous dose, the estimated bioavailability (the share of a dose that ends up acting) was 77% for subcutaneous injection, 4.8% for the nose and 0.3% by mouth. These figures were worked out from the growth-hormone response, not by measuring hexarelin in the blood, so researchers call them "biological" bioavailability. [2]

Doserly

How much of a hexarelin dose acted, by route

Human study (single doses) plus a laboratory gut study

12 healthy young adults, single doses, 1994. Estimated share of the dose that acted (IV = 100%). Linear scale.

Intravenous (reference)

100%

Study dose: 1–2 mcg per kg

Subcutaneous injection

77%

Study dose: 1.5–3 mcg per kg

Nasal spray

4.8%

Study dose: 20 mcg per kg

Swallowed (oral)

0.3%

Study dose: 20–40 mg (20,000–40,000 mcg)

Estimated from the growth-hormone response, not from drug levels in blood.

Why oral fails: gut enzymes including trypsin break hexarelin down, and little crosses the gut lining (lab study).

PMID 8126144; gut breakdown: PMID 11578108. Study doses, not recommendations.

IV is the 100% reference. By the other routes a smaller share of each dose acted, so much larger doses were needed for a similar growth-hormone response.

Is there a nasal spray or oral hexarelin?

Both were tested decades ago. Nasal doses of about 20 mcg per kilogram, more than ten times the injected amount, released as much growth hormone as a small intravenous dose, and children used nasal hexarelin three times a day for months in growth studies. In rabbits, a nasal dose reached the brain and spinal fluid at higher levels than the same dose given into a vein. [96], [10], [97]

By mouth, 20 mg (20,000 mcg) was needed for a clear effect, and that dose three times a day for 15 days slightly raised IGF-1 in older women. Swallowed hexarelin is broken down in the gut: digestive enzymes, including trypsin, cut it into a breakdown product, and very little crosses the gut wall. In rat experiments, some absorption enhancers (chitosan and EDTA) let more through the gut lining while others did not, but no oral hexarelin product has been developed from this work. [2], [36], [98], [99], [100]

Some people take hexarelin under the tongue (sublingually) from an injectable vial. That route has never been tested, and given how poorly hexarelin is absorbed by mouth, there is no basis for assuming it works. [43], [2]

How long does hexarelin last in the body?

Hexarelin's own half-life in people has not been published. The 55 minutes quoted on many dosing pages comes from a 1994 study in which it describes how fast growth hormone, not hexarelin, left the blood after an intravenous dose; that study did not measure hexarelin itself. In a later study, growth hormone cleared in about 25 minutes in the morning and about 65 minutes during sleep. [34], [78]

What is known in people is the shape of the response. After an intravenous dose, growth hormone peaked within 15–30 minutes and was back to baseline within about 4 hours. After a nasal dose it peaked later, at 30–60 minutes. [34], [49], [96]

Animal measurements give a rough idea. Given into a vein, hexarelin's half-life was about 76 minutes in rats and 120 minutes in dogs; in rats, 64% of a subcutaneous dose reached the blood, and exposure rose in step with the dose across three single doses. In a lab test with human blood plasma, about 65% of hexarelin was bound to proteins. These numbers cannot simply be carried over to people. [101], [102], [103]

Half-life is not the same as how long any effect lasts. For hexarelin, the practical point is that each growth-hormone pulse is over within a few hours.

Is hexarelin the same as examorelin, Tyr-Ala-hexarelin or GHRP-6?

Hexarelin and examorelin are the same substance: examorelin is its international nonproprietary name. It was made by modifying GHRP-6, and it is a separate peptide from GHRP-6 and from GHRP-2, which differ in their amino acids. Tyr-Ala-hexarelin is a longer, eight-amino-acid research version made for laboratory binding tests; in seven volunteers it acted like hexarelin, but it is a different molecule. [1], [7], [6], [104]

Does the injection site matter?

No study has compared injection sites. Two people describe local reactions, one a red, swollen patch about 3 inches across that took about 3 days to settle, and one redness and itching that started with a second vial. [105], [106] See unwanted effects.

How should hexarelin be stored, and how long does it last?

How long hexarelin keeps its strength is not established. No stability study of hexarelin prepared for injection has been published, so the storage windows below come from sellers and protocol pages, not from a tested medicine label.

• Powder, before mixing. Hexarelin is sold as a freeze-dried powder. One protocol page advises storing it sealed, dry and dark at −20 °C and says its two tryptophan building blocks are sensitive to light and oxidation. That is chemically plausible but has not been tested for hexarelin. [107]
• After mixing. For hexarelin mixed into liquid (reconstituted), pages say to keep it in the fridge at 2–8 °C and use it within 28 days, 3–4 weeks or about 4 weeks. None cites a stability test. [13], [16], [15], [108]
• The only measured numbers. An anti-doping laboratory stored tiny amounts of hexarelin as reference samples, mixed with about 40 other peptides in a mildly acidic liquid. Over 12 months, about 8% was lost in solution at −20 °C, but 10–30% when samples were dried and kept at −20 °C, one of the poorer results in the mix. These were laboratory standards, not vials mixed for injection, so they cannot set a storage rule. [109]
• The mixing liquid. The label of bacteriostatic water, the liquid these pages usually name, says not to store drug solutions made with it unless the drug's maker says so. There is no approved maker of hexarelin to say so. [110]

Tested rules for related approved medicines are much stricter: Japan's GHRP-2 diagnostic has confirmed stability for only 24 hours after mixing, and mixed macimorelin must be used within 30 minutes. Those rules belong to those products, not to hexarelin. [111], [112]

In community education groups, some members advise freezing the powder. That has not been tested for hexarelin either. This guide does not cover mixing or injection technique; the Academy note below covers practical handling.

What do we actually know about hexarelin in people?

Quite a lot about its hormone effects, but almost all of it is old, small and short. University endocrinology groups published dozens of human studies between 1994 and 2004, nearly all giving one test dose and measuring hormones over the next few hours. Only a handful gave hexarelin for weeks or months, and none of those longer studies describes a placebo group in its abstract. Searches of ClinicalTrials.gov and the European, WHO, UK and Japanese trial registries under its known names found no registered trial of hexarelin; most of the studies predate those registries. [34], [3], [11], [12]

What did the single-dose studies show?

A few patterns hold across these studies. The growth-hormone response is large and reliable when a person is fasting, smaller after food, smaller in older adults and absent when the pituitary is damaged. Prolactin, ACTH and cortisol rose with it in these single-dose studies, and the size of those rises did not shrink with age. [48], [35], [114]

What happened with repeated use?

This is where hexarelin's research record is most useful for anyone reading protocol pages, because it shows what happened over weeks and months.

• 16 weeks in older adults. Twelve healthy older adults had subcutaneous injections of 1.5 mcg per kilogram twice a day. The growth-hormone response to a test dose fell by about 31% after 1 week and about 45% by week 16 (the fall was statistically significant from week 4), then returned to its starting level 4 weeks after stopping. IGF-1, the related binding protein IGFBP-3, total body fat, lean body mass and bone density did not change significantly; only one marker of bone formation rose. [3], [28]
• Stress hormones over the same 16 weeks. The cortisol response to each morning dose was about 19% smaller at week 16 and back to normal 4 weeks after stopping. Daily cortisol output in urine and resting cortisol did not change, and neither did the ACTH and prolactin responses to a dose. The authors concluded that with this schedule, "over-stimulation of the pituitary adrenal axis and prolactin secretion do not occur". [94]
• One day of repeated injections. In six young men, two or three injections in a day raised total growth-hormone release equally and did not change prolactin, ACTH, cortisol or IGF-1 over those 24 hours. The earlier injections blunted the growth-hormone rise to a later test dose and removed its ACTH and cortisol rise. [27]
• Short nasal and oral courses in older adults. Eight days of nasal doses or 15 days of oral doses did not weaken the growth-hormone response. The oral course slightly raised IGF-1, and neither changed prolactin or cortisol or caused side effects. [36]
• Months of nasal doses in children. In short children, nasal hexarelin three times a day for up to 8 months raised IGF-1 and growth speed, "seemingly without undesirable side-effects". In a similar group, the growth-hormone response halved within a week and stayed lower, yet growth still sped up. [10], [37]

Doserly

The response faded, then came back

Human study (uncontrolled, n=12)

µg/L·h (growth-hormone area under the curve)

1.5 mcg per kg subcutaneous, twice daily, 16 weeks, 12 healthy older adults; no comparison group described

Weeks 0–16: twice-daily injections. Weeks 16–20: stopped.

Start (week 0)

19.1 µg/L·h

Week 1

13.1 µg/L·h

Week 4

12.3 µg/L·h

Week 16

10.5 µg/L·h

4 weeks after stopping (week 20)

19.4 µg/L·h

Unchanged at week 16

IGF-1body fatlean massbone density

PMID 9589671; PMID 10990150. Uncontrolled study; study regimen, not a recommendation.

The response fell during 16 weeks of injections and returned near its starting level 4 weeks after stopping.

These studies were small, and most were run by a few research groups. The 16-week results come from one group of 12 people with no comparison group described, and neither abstract reports side effects, so tolerability over those weeks is not documented in the published summaries. [3], [94]

What did the heart studies show?

Five small reports gave one intravenous dose and measured the heart's pumping strength (some compared their results with groups studied earlier), recorded as the ejection fraction (the share of blood the main pumping chamber pushes out with each beat):

• Healthy men (7). Ejection fraction rose from 64.0% to 70.7%, starting at 15 minutes and lasting up to 60 minutes, with no change in blood pressure or heart rate. The same amount of growth hormone given directly had no effect. [47]
• Adults with growth-hormone deficiency (7) and healthy controls (9). It rose in both groups, even though hexarelin released almost no growth hormone in the deficient patients. [57]
• Men having heart bypass surgery (24), under anaesthesia. Ejection fraction and the heart's output rose within 10 minutes and stayed higher for up to 90 minutes. GHRH, growth hormone and placebo had no such effect. Blood pressure rose slightly. [58]
• Severe heart failure (two studies). Ejection fraction rose in people whose heart damage came from blocked arteries, but not in people with dilated cardiomyopathy. [59], [60]

These show a short-lived, measurable effect on heart pumping that does not depend on growth hormone. They do not show that hexarelin protects the heart over time, improves symptoms or prevents heart attacks; no human study has tested that. [58]

Was hexarelin ever tested as a medicine?

Yes, for two uses, and neither led to approval. As a diagnostic test, a single dose of hexarelin was a reasonable screen for growth-hormone deficiency in adults, but not a good test of the stress-hormone system. As a growth treatment, nasal hexarelin raised growth speed in small groups of short children. Neither use reached a registered trial or an approval, and a related peptide, GHRP-2, later became an approved diagnostic test in Japan. [9], [10], [111], [11]

Does more growth hormone mean better health?

Not automatically. A growth-hormone pulse, an IGF-1 result, a change in muscle or fat and feeling better are four different outcomes. For hexarelin, the first is well documented; the second did not change over 16 weeks in older adults; the third did not change either; and the fourth has never been measured in a study. A larger growth-hormone pulse on a blood test is not evidence of a benefit. [3], [2]

How does hexarelin work?

Hexarelin switches on the ghrelin receptor (GHS-R1a) on growth-hormone-making cells of the pituitary gland and on nerve cells in the hypothalamus, the brain region just above it. The pituitary answers with a burst of stored growth hormone. In human pituitary tumour cells grown in a dish, hexarelin released up to 4.6 times more growth hormone than untreated cells, much as GHRP-6 did. [5], [35]

The growth-hormone response depends on the brain's own releasing hormone, GHRH. In four adult men born with a faulty GHRH receptor, hexarelin released no growth hormone at all, yet their prolactin, ACTH and cortisol rose normally. In people whose pituitary is disconnected from the hypothalamus, it released little or no growth hormone. [50], [114]

Why does it raise cortisol and prolactin?

Hexarelin is not selective for growth hormone. In healthy adults, a single dose raised ACTH (the pituitary hormone that tells the adrenal glands to make cortisol) and cortisol about as much as a standard dose of corticotropin-releasing hormone, the body's main stress-hormone signal. The effect probably runs through a different signal, vasopressin. It also raised prolactin, a pituitary hormone best known for milk production, by up to about 180% at the top of the dose range. [30], [89], [29]

In people with Cushing's disease, caused by a small ACTH-making pituitary tumour, the ACTH and cortisol response was several times larger than normal, which is why anyone with a pituitary or adrenal condition has reason for caution. [30], [115]

Why is it paired with GHRH?

The pituitary has two main "release" switches for growth hormone: GHRH presses one, ghrelin and hexarelin press the other. Given together in healthy men, the natural hormone's short form, GHRH(1-29), and hexarelin released more growth hormone than the sum of the two alone, and in older men GHRH or the amino acid arginine boosted the smaller response to hexarelin. The extra effect of the pair disappeared when both were given again one or two hours later. [38], [48]

What is CD36, and is the heart effect unique to hexarelin?

Researchers looking for the reason hexarelin affects the heart found a second binding site in rat heart tissue: CD36, a receptor on heart muscle cells, blood-vessel lining and immune cells that helps cells take up fats. In isolated rat hearts, hexarelin narrowed the heart's own blood vessels through CD36, an effect that was missing in hearts lacking CD36. The exact binding spot on CD36 overlaps the site used by oxidized cholesterol particles. [116], [117], [118]

In rats with no pituitary gland, and so no growth hormone, hexarelin still protected the heart from damage when its blood supply was cut and restored, while a similar peptide that does not bind heart tissue did not. That supports a direct heart action, as the human single-dose studies also suggest. [119], [47]

CD36 is not unique to hexarelin. The 2002 study that identified it describes it as mediating the heart actions of GHRPs as a group, and in rats with heart failure GHRP-1, GHRP-2, GHRP-6 and hexarelin all improved heart function. Some protocol pages present CD36 as a unique hexarelin advantage; the research does not support that. [117], [120], [87], [24]

Does the body get used to it?

Yes, partly and reversibly. This is called desensitization. In a cell study using cells that carry the human ghrelin receptor, the signal faded within 2–5 minutes of a first dose. In people, a second intravenous dose two hours after the first produced a much smaller growth-hormone response, and the fading over weeks of use recovered after stopping. [121], [122], [3]

Animal studies point both ways: in young dogs on large twice-daily doses the response fell below its starting level by week 6, while in old rats it held up for 30–60 days. Whether the heart effects fade in the same way has not been studied. [92], [123]

Does it affect appetite and blood sugar?

Ghrelin is best known as a hunger hormone, and hexarelin shares some of that effect. In people, a single dose caused a small, short-lived rise in appetite. In rats, a daily dose kept food intake higher for 8 weeks without changing body weight. Unlike natural ghrelin, a single dose did not change blood sugar or insulin; what is known about longer use is covered under risks. [89], [124], [113]

What are the risks and unanswered questions?

Is hexarelin safe?

Its safety for the way people use it today has not been established. The human studies were small and mostly gave one dose; the longest adult course was 16 weeks in 12 older adults, and no fixed-microgram schedule has ever been tested. Within those limits, the studies that reported on tolerability describe no serious problems: brief flushing and slight drowsiness after single doses, with no clinically significant adverse events in the dose-finding study. One study of 60 children and young people states that none "experienced adverse side effects", and short nasal and oral courses in older adults caused none. [3], [34], [2], [49], [36]

Short, small studies can miss uncommon problems and anything that takes months to appear. We found no published case reports and no ongoing safety surveillance of the kind that exists for approved medicines, which reflects how little it has been studied, not proof that nothing has happened.

What hormone changes does it cause?

• Prolactin, ACTH and cortisol rise after single injected doses. The rises are dose-related and short-lived: in children they were back to baseline within 2 hours. At the top of the dose range, prolactin rose by up to about 180%, while a very low dose given with GHRH raised prolactin moderately and cortisol not at all. After a day of two or three injections, a further test dose no longer raised ACTH or cortisol. [29], [30], [49], [27]
• They were not chronically raised over 16 weeks. With twice-daily injections of 1.5 mcg per kilogram, daily cortisol output and resting cortisol did not change, the ACTH and prolactin responses to a morning test dose stayed the same, and the cortisol response to it became smaller. Higher or more frequent amounts have not been tested. [94]
• Thyroid-stimulating hormone (TSH) shifted within the normal range in two small studies of children: down after one dose and up after a week of nasal doses. [96], [125]
• Lipoprotein(a) rose by about 102% in six boys given nasal hexarelin for 6–9 months, a change also seen with growth-hormone treatment. Lipoprotein(a) is a blood fat linked to heart disease risk. [126]

What side effects do people report?

The published studies describe only brief flushing and drowsiness after single doses, and the summaries of the longer studies do not report side effects. Personal accounts, almost all involving other peptides or steroids at the same time, add hunger after each dose, poor sleep or anxiety after evening doses, tingling or numb hands like carpal tunnel syndrome, head rushes, bloating and water retention, injection-site reactions, one report of slight milk leakage from the nipples and one of a rising resting heart rate. [127], [66], [128], [129], [130], [131], [69], [105], [132] See the accounts in detail.

Several of these match the known effects of growth hormone and its relatives. Approved growth-hormone labels list swelling, joint and muscle pain and nerve compression, including carpal tunnel syndrome and tingling, and a 2026 review of this class of peptides lists hormone changes, appetite changes, blood-sugar problems, fluid retention, muscle and joint pain and injection-site reactions. [133], [134]

Can hexarelin make sleep worse?

It can. In the only sleep study, seven healthy young adults received four doses between 10 pm and 1 am. Deep (slow-wave) sleep in the first half of the night and the brain-wave activity that marks it both fell, while growth hormone, prolactin, ACTH and cortisol rose. The authors suggested that the shift toward stress-hormone signalling explains the poorer sleep. [31]

Does hexarelin raise blood sugar?

Not after a single dose: in 11 young adults, hexarelin did not change blood sugar or insulin, while natural ghrelin raised blood sugar. Longer-term effects in adults were never measured. In six boys given nasal hexarelin for months, fasting insulin rose sharply, and related drugs acting on the same receptor raised blood sugar in longer trials, so a class effect is plausible. [113], [126], [135], [136]

Could hexarelin affect fertility or pregnancy?

There are no human data. In mice, daily injections reduced ovulation, and at the higher dose tested fewer fetuses developed for each egg released. Mice exposed in the womb during the first week of pregnancy later learned less well, and adult mice given hexarelin long term did too. Animal findings like these do not predict human effects precisely, but they are a clear reason for caution. [32], [137]

Does hexarelin cause cancer?

Nobody knows. There are no human data on cancer and no long-term animal cancer studies. The concern comes from growth hormone itself: approved growth-hormone medicines carry warnings about tumours, and there are no data to rule out a similar risk from raising growth hormone repeatedly with hexarelin. [133], [135]

Could product quality change the risk?

Yes. We found no approved hexarelin product in any country we checked, so what is sold is compounded or labelled for "research use only". An anti-doping laboratory noted in 2012 that all peptides of this family except GHRP-2 are unapproved drugs, yet readily available online. Health Canada warns that unauthorized injectable peptides may cause infection and allergic reactions, and FDA does not review compounded drugs for safety, effectiveness or quality before they are sold. In December 2025, FDA warned a US bulk-ingredient distributor whose "Hexarelin Acetate" drug listing named a different peptide as the active ingredient in its own labeling file. One person blamed a skin reaction on the mixing liquid, and another suspected an impure second vial. [138], [33], [139], [140], [105], [106]

Is hexarelin legal? Is it FDA-approved?

Checked September 24, 2026. Rules differ by country and change quickly.

United States. Hexarelin is not an FDA-approved medicine, and no approved product contains it. It is also absent from FDA's published compounding lists:

• FDA's lists of bulk substances nominated for compounding by pharmacies (updated May 14, 2026) and by larger outsourcing facilities (updated March 21, 2025) do not include hexarelin or examorelin. [141], [142]
• FDA's list of compounding substances that may present significant safety risks ("Category 2", content current as of April 22, 2026) does not include it either, although it includes GHRP-2, GHRP-6, ipamorelin and ibutamoren (MK-677). [143]

In practice, none of FDA's published compounding categories includes hexarelin, unlike its relatives. That absence is not a sign that hexarelin has been cleared. It is compounded anyway: a February 2025 FDA inspection report for a Texas compounding pharmacy lists "Hexarelin 6 mg per Vial for Injection" among its sterile products, and some clinics and aesthetic businesses offer it. An FDA substance code (UNII) for examorelin exists, but FDA states that such a code "does not imply any regulatory review or approval". [139], [144], [45], [145]

Canada. Health Canada's advisory on unauthorized injectable peptides seized from a Canadian seller (last updated August 1, 2025) names hexarelin. It states that injectable peptides are regulated as prescription drugs in Canada and that none of the seized products had been authorized. Health Canada's Drug Product Database lists no product containing hexarelin or examorelin. [33], [12]

Australia. Hexarelin is a prescription-only medicine (Schedule 4) in the June 2026 Poisons Standard, and it is also listed among substances that are illegal to possess without authority, such as a prescription, under the law of the state or territory where it is held. It was added to both lists by a scheduling decision in March 2015 that took effect on June 1, 2015. Scheduling controls supply; it does not mean an approved product exists, and we could not search Australia's register of approved medicines. [146], [147]

New Zealand. The Medicines Classification Committee classified hexarelin, along with ipamorelin and tesamorelin, as a prescription medicine in November 2013. [148]

European Union. We found no marketing authorization. The European Medicines Agency's only mention of hexarelin is as a comparison in rats inside the assessment of a different medicine, macimorelin. [149]

A "research use only" label does not make a product legal to sell for human use, or safe.

Is hexarelin banned in sport? Does it show up on a drug test?

Yes, it is banned. The World Anti-Doping Agency names "examorelin (hexarelin)" in section S2.2.4 of its Prohibited List, among growth-hormone-releasing peptides, prohibited in and out of competition on both the 2026 list and the 2027 list that takes effect on January 1, 2027. [8], [150]

It is detectable. Anti-doping laboratories have published urine tests that include hexarelin. In a one-volunteer nasal-dose study, hexarelin was broken down extensively, and one breakdown product was still found in urine after the peptide itself had cleared. The authors note that detection time depends on the person's metabolism, the product and the route. A positive result is not always proof of hexarelin itself: in human liver cells, the related peptide alexamorelin breaks down into hexarelin. [151], [152], [153], [154]

Who should be especially cautious?

For most of these groups there are no safety data in people. That is a reason for caution, not proof of harm.

• Pregnancy, breastfeeding or trying to conceive. No human data; mouse studies found lower ovulation and fewer developing fetuses. [32], [137]
• Diabetes, prediabetes or insulin resistance. Long-term blood-sugar effects are unknown, fasting insulin rose in boys on long-term nasal doses, and related drugs raised blood sugar. [126], [136]
• A history of cancer. Growth-hormone labels carry a tumour warning. [133]
• Pituitary or adrenal conditions, including Cushing's disease, or a history of high prolactin. The cortisol response can be several times larger than normal, and prolactin rises after injected doses. [115], [29]
• Heart disease. Hexarelin changes heart pumping within minutes and narrowed heart blood vessels in rat hearts. It has not been tested as a heart treatment and is not a substitute for one. [58], [117]
• Sleep problems. Night-time doses reduced deep sleep. [31]
• Under 18. Studies in children were medical research with close monitoring, and lipoprotein(a) and insulin rose during months of use. This guide is written for adults. [126]
• Competitive athletes. It is banned at all times. [8]
• People taking other medicines, especially corticosteroids such as prednisone or diabetes medicines. Interactions have not been studied; see the next question.

Has hexarelin been tested alongside other medicines?

Not in any study of medicines people take for health conditions. The combinations tested in people were research tools given once: GHRH, arginine, ghrelin, corticotropin-releasing hormone, desmopressin and somatostatin. Sex hormones changed the response: a testosterone injection a week earlier increased the growth-hormone response in boys with delayed puberty, while estrogen replacement did not restore the smaller response seen after menopause. [48], [4], [89], [155], [49], [156]

Nothing has been published on hexarelin with corticosteroids, diabetes medicines, GLP-1 medicines, testosterone therapy or other peptides taken for weeks. Because hexarelin raises cortisol and may affect insulin, combining it with medicines that act on those systems is untested territory. Bring a complete list of everything you take to a pharmacist or doctor. [30], [126]

What should be monitored while using hexarelin?

There is no official monitoring plan, because no regulator has approved hexarelin for any use. What exists is what the human studies measured, what a 2026 medical review suggests for this class of peptides, and what the labels of related approved medicines require. It can help you prepare questions for a clinician; it is not a personal testing plan. [11], [134]

What did the human studies check?

The studies measured growth hormone after each dose and over 24 hours, IGF-1 and its binding protein IGFBP-3; prolactin, ACTH and cortisol, including 24-hour urine cortisol; thyroid hormones; body fat, lean mass and bone density by DXA (dual-energy X-ray absorptiometry) scan with blood markers of bone turnover; blood sugar and insulin after single doses, and lipoprotein(a) and insulin during months of nasal use in children; ejection fraction, blood pressure and heart rate in the heart studies, plus a 4-hour ECG after each dose in the dose-finding study, which found no clinically significant changes; and brain-wave sleep recordings. [3], [27], [29], [94], [96], [113], [126], [47], [34], [31]

What was not reported. No published hexarelin study we found reports HbA1c or fasting blood sugar over weeks of use, heart tracings (ECGs) during repeated use, fluid retention or swelling scores, or antibodies against the drug. Not reported does not mean not measured, but there are no results to go on.

What do the review and related-drug labels suggest?

These are class-based considerations for medicines that raise growth hormone or act on the same receptor, not hexarelin findings or a testing schedule.

• A 2026 review for doctors says fasting blood sugar or HbA1c is "worth obtaining" whichever of these peptides someone uses. It notes that raised cortisol and prolactin are mainly a feature of the older peptides in this family, including hexarelin, and suggests that a mildly high cortisol result is retested after a break before the pituitary is investigated with scans. [134]
• Growth-hormone medicines warn about fluid retention (with swelling, joint and muscle pain, carpal tunnel syndrome and tingling), lower insulin sensitivity and the growth of existing tumours. The somatropin label tells prescribers to check blood sugar periodically in everyone taking it. Hexarelin raises growth hormone in short bursts rather than supplying it, and none of these effects has been studied with it. [133]
• Macimorelin, an approved US diagnostic that acts on the same receptor and is swallowed once, lengthened the QT interval (a measure of the heart's electrical recharge) by about 10 milliseconds at four times its test dose, and its label warns against combining it with other drugs that do the same. No hexarelin study has reported the QT interval; the one study that monitored ECGs after single doses found no clinically significant changes. [112], [34]

Which signals matter, and why?

Every row comes from the studies, labels and accounts cited above. [3], [113], [126], [136], [94], [31], [89], [66], [129], [105], [131], [132], [128], [47], [133]

A growth-hormone level on its own says little, because after a test dose the pulse was over within about 4 hours. [34] A single IGF-1 or prolactin result is also hard to read without a starting value. The more careful courses in community education groups advise testing IGF-1, fasting blood sugar and HbA1c before a block and a few weeks in. No study has tested any testing schedule, so discuss testing with a clinician.

What do people in public communities report?

Hexarelin has a big reputation and few first-hand users. In the community education groups we reviewed, courses describe it often, usually as the strongest and fastest-fading peptide of its kind, but members rarely report using it, and no member gave a personal dose alongside a result. Public forums have more first-hand accounts, posted between 2007 and 2026, and almost every one involves other compounds in the same routine: a GHRH peptide (CJC-1295 with or without DAC, or sermorelin), another growth-hormone peptide, IGF-1 LR3 or anabolic steroids. Several of the most detailed logs were posted by people who said they represented a seller. What follows are experiences with hexarelin-containing routines, not effects that can be pinned on hexarelin alone. [129], [157], [158], [43], [159], [160], [130]

What do the positive reports look like?

They are few, varied and mixed with other changes:

• Pumps, fullness and a leaner look. Several people describe strong "pumps" when injecting around training. One, taking 100 mcg before and after workouts without CJC-1295, said they looked leaner; another felt fuller but no stronger. A seller's representative described fullness and more intense workouts within about 15 minutes of a dose. [131], [51], [159]
• Strength. A 55-year-old taking hexarelin with CJC-1295 before training and at bedtime, 3 days on and 2 days off, said they were getting stronger, building muscle and sleeping better a couple of weeks in. An essay reprinted on a forum in 2007, by a writer on prescribed hormone replacement, reported some strength and a little fat loss on 200 mcg a day. [52], [161]
• Water weight, sleep and recovery. After a month of 200 mcg a day with CJC-1295, one person said they lost water weight, looked more defined and slept very well; another, on a steroid cycle, credited it with better sleep and recovery. [162], [163]
• Energy and weight. One person with a complicated medical history said hexarelin "resolved my fatigue entirely", without hormone tests to show why; another gained about 12 pounds over 8 weeks on a blend, without saying whether it was muscle, fat or water. [164], [165]
• An older forum report. In 2009, one person described running 500 mcg a day in blocks of 4 weeks on and 4 weeks off for three months, with "some strength gains and fat loss" and no side effects they noticed. [166]

In community education groups, the one member who reported a clear result after a stated time described more strength and a little extra size, but nothing dramatic, after 4 weeks run straight after a course of CJC-1295 and ipamorelin.

How long do people run it, and when do they notice anything?

Most plans are short. One person's doctor instead advised 5 days on and 2 days off with no end date, to limit the fading, and a forum user who felt the effect weaken after 10 straight days switched to the same pattern. A seller's representative who took one day off a week said the effect stayed strong. [52], [85], [159] Members of community education groups who describe their own use almost all run hexarelin for about 4 weeks, then take a month off everything that raises growth hormone, mainly out of concern that the effect fades. In public threads, people asking why they should not run it for 20 weeks were told about hunger, cortisol and cost, and another cited the 16-week study showing the response recovered within 4 weeks of stopping. [167], [168]

Reported time frames range from a pump within minutes and more stamina after one week to no change after three months. No account included blood tests showing what hexarelin did to growth hormone or IGF-1; two people claimed a high IGF-1 result but gave no number. [159], [52], [45], [169], [170]

Does everyone notice a difference?

No. People describe feeling nothing after 100 mcg and then 200 mcg on consecutive days, no difference from their earlier ipamorelin and CJC-1295 routine, no muscle benefit, progress that was "nothing mind blowing", a slightly tighter waist that was not worth the cost, and, on a course prescribed by a clinic, no difference at all by the third month. In community education groups, one member noticed nothing after a 4-week block and said they would not use it again. [51], [165], [53], [130], [171], [45]

This matches the research better than the reputation does. A strong growth-hormone pulse after each dose did not change IGF-1, muscle or fat over 16 weeks in older adults. [3]

What unwanted effects come up?

• Hunger. Several people describe strong hunger soon after each dose, one "without fail", with a gurgling stomach that they did not get from ipamorelin. [127], [165], [164]
• Sleep and mood. One person taking 100 mcg morning and evening said it kept them up "all night" and heightened their emotions, and stopped after about 20 days. Others slept worse for the first few days, fell asleep about two hours later after a bedtime dose, or, on a combination with sermorelin, had anxiety and racing thoughts at night after the fifth evening injection and still felt stimulated after lowering the dose. On the other side, people describe wanting to sleep for 10 hours, or marked tiredness for a while after a dose. [66], [129], [164], [172], [128], [43], [160], [130]
• Hands and legs. Tingling like carpal tunnel syndrome in the hands within minutes of each injection, with aches in the legs and feet, in a 21-day log; numb hands in several other accounts, in one case severe after higher bedtime doses. [129], [157], [159], [160], [130]
• Flushing, head rushes and a "high". A warm head flush lasting a few hours and a slightly euphoric feeling after a morning blend, and strong head rushes or hot flushes in other accounts. One of those people noticed a small amount of milk leaking from the nipples, which fits a prolactin rise, but no blood test was done. [157], [173], [131]
• Bloating and water retention. One person blamed bloating on hexarelin and said it later eased; another noted some water retention. [69], [160]
• Heart rate and "cortisol". One person noticed their resting heart rate creeping up and considered stopping, and another described a "higher cortisol" feeling; neither posted measurements. [132], [158]
• Injection-site reactions. A red, swollen patch about 3 inches across that took about 3 days to settle, and redness and itching that began only with a second vial. [105], [106]

No member of the community education groups we reviewed described a side effect clearly linked to hexarelin; the one explicit note was of no reaction at all. That reflects how few members use it, not proof that it is well tolerated.

What do community education groups teach?

Courses mostly agree on a few practical rules: 100–200 mcg per injection once or twice a day, on an empty stomach, in short blocks, and never combined with ipamorelin or another peptide that acts on the same receptor, although one contest-preparation plan in the same material layers it on GHRP-2. Pairing it with a GHRH peptide such as CJC-1295 is widely endorsed. When members ask about hexarelin, educators often steer them toward ipamorelin or tesamorelin because of cortisol and prolactin. The more evidence-focused courses are the most sceptical, and one rates the case for hexarelin as weak.

Some teaching goes further than the research: that hexarelin is clearly the most potent GHRP, that tolerance becomes permanent, that it causes lasting cortisol and prolactin overload, that it improves sleep or insulin sensitivity, and that its half-life is 30 or 60 minutes. The human studies do not support any of these, as the sections on repeated use, stopping and half-life explain. [6], [3], [94], [31]

How can you judge a hexarelin story?

Ask what exactly was taken and how much (hexarelin alone or in a blend, per injection or per day), what else changed (other peptides, testosterone or other steroids, a GLP-1 medicine, diet, training), whether it came straight after another growth-hormone course, whether blood tests were done before and during use and the actual numbers shared, whether the writer sells peptides, and what happened later. A blend story cannot tell you which peptide did what, and a single good month cannot show what happens over a longer course.

These selected discussions show which questions and experiences matter to people. They are not a survey of all users, a response rate or a substitute for controlled studies.

How does hexarelin compare with GHRP-2, GHRP-6, ipamorelin and MK-677?

All five act on the same ghrelin receptor. CJC-1295, sermorelin and tesamorelin work through the GHRH receptor instead, and each has its own guide covering its evidence and approval history. Protocol amounts in the table come from websites, not tested doses. [8]

The differences that matter are practical. Hexarelin's research record stands out for its single-dose human heart studies and for a 16-week study showing how fast its growth-hormone effect fades and returns. It is also the only one of the five that is on none of FDA's published compounding lists, which is not a sign that it was cleared. No study has compared any of them for muscle, fat, sleep or safety, so the table cannot say which works better. [58], [3], [141] See also the Doserly guides to CJC-1295, sermorelin, tesamorelin and the CJC-1295 and ipamorelin blend.

Common questions about hexarelin

How long does hexarelin take to work?

There is no established timeline for any felt benefit. Growth hormone peaks within about 30 minutes of an intravenous test dose and is back to baseline within about 4 hours, but that is a blood-test effect, not a result, and in the 16-week adult study IGF-1, lean mass and body fat did not change. Personal accounts range from more stamina in the first week to no difference after three months. [34], [3], [52], [45] See what people report.

Is hexarelin FDA-approved, and is it legal to buy?

No. We found no approval in any country we checked, and whether it is legal depends on where you live. In the US it is not an approved drug and is not on any of FDA's published compounding lists; Health Canada names it among unauthorized injectable peptides; in Australia it is prescription-only and illegal to possess without authority under state or territory law, and New Zealand classifies it as a prescription medicine. A "research use only" label does not make it legal to sell for human use. [143], [33], [146], [148] See the dated legal-status summary.

Is hexarelin stronger than ipamorelin or GHRP-2?

Not clearly. In the one human head-to-head study, hexarelin and GHRP-2 released similar amounts of growth hormone and raised prolactin, ACTH and cortisol by similar amounts, and natural ghrelin released more than hexarelin. No human study has compared hexarelin with ipamorelin. "The strongest GHRP" is a reputation, not a measured result. [6], [4] See how it works.

Does hexarelin stop working, and how long a break is needed?

Its effect fades but comes back. With twice-daily injections, the growth-hormone response was about 45% lower after 16 weeks and back to its starting level 4 weeks after stopping. Protocol sources most often suggest 4 weeks on and at least 4 weeks off, but no study has compared break lengths. [3], [13] See what happens when you stop.

Can hexarelin be taken with ipamorelin or CJC-1295?

Most sources pair it with a GHRH peptide such as CJC-1295 without DAC and advise against combining it with ipamorelin. In people, hexarelin and GHRH together released more growth hormone than the two added together, although that extra effect disappeared on a repeat dose an hour or two later; that study used the natural hormone's short form, and hexarelin has not been tested with CJC-1295 itself. For two peptides that act on the same receptor, the one human test found no added effect: ghrelin plus hexarelin released no more growth hormone than ghrelin alone. [38], [4] See combinations.

Is hexarelin good for the heart?

It is not proven to be. One intravenous dose briefly increased the heart's pumping in small human studies, but not in people with dilated cardiomyopathy, and heart protection over weeks has been shown only in rats and mice. No human study has tested repeated doses for the heart or measured heart attacks or survival. [47], [59], [61] See the heart studies.

Does hexarelin make you hungry?

It can, although how often during regular use is unknown. In healthy young men, a single dose caused a small, short-lived rise in appetite, and in rats daily doses kept food intake up for 8 weeks. Personal accounts describe strong hunger soon after each dose, which some people did not get from ipamorelin. [89], [124], [127] See unwanted effects.

Is hexarelin a steroid, or is it growth hormone?

Neither. Hexarelin is a six-amino-acid peptide that prompts the pituitary to release the body's own growth hormone in short pulses. Growth hormone itself is a much larger protein sold as prescription medicines, and anabolic steroids are a different kind of molecule. It is still banned in sport at all times. [1], [133], [8]

Glossary

Plain explanations of the route, dosing and research terms used in this guide. Underlined terms in the text link here.

ACTH and cortisol

ACTH (adrenocorticotropic hormone) is a pituitary hormone that tells the adrenal glands to release cortisol, the body's main stress hormone. Single injected doses of hexarelin raised both for a few hours.

Adverse event

A harmful or unwanted medical event reported after someone used a treatment. A report alone does not prove the treatment caused it.

Amino acid

A small chemical building block. Chains of amino acids make up peptides and proteins.

Animal study

Research in animals such as rats, mice or dogs. It shows what a substance does in a living body, but results in people can differ.

Bioavailability

The share of a dose that reaches the bloodstream and acts. For hexarelin in people it has only been estimated by comparing the growth-hormone response with an intravenous dose (biological bioavailability): about 77% for subcutaneous injection, 4.8% in the nose and 0.3% by mouth.

Blend

A product or routine that combines hexarelin with other peptides, such as CJC-1295, in one vial or one injection. The blend's total amount is not its hexarelin amount.

CD36

A receptor on heart muscle cells, blood-vessel lining, fat cells and immune cells that helps cells take up fats. Hexarelin and related peptides also bind to it, which may explain some of their heart effects in animals.

Cell study (in vitro)

Research on cells grown in a dish. It gives early clues about biology, but it is far from proof of benefit in people.

CJC-1295

A lab-made version of growth-hormone-releasing hormone. The version without DAC (drug affinity complex), also sold as Mod GRF 1-29, is short-acting and is the one usually combined with hexarelin; the version with DAC lasts much longer.

Compounding

When a pharmacy prepares a customized medicine from individual ingredients. In the US, federal lists control which bulk ingredients pharmacies and larger outsourcing facilities may use.

Controlled trial

A study that compares people who receive a treatment with a similar group who do not, often receiving a placebo instead. Controlled studies of hexarelin measured short-term hormone and heart responses; none tested muscle, fat loss, recovery or long-term heart health.

Course and cycle

A course is the period of repeated use, such as 4 weeks. A cycle is a course plus a planned break before any further use.

D-amino acid

The mirror-image form of an amino acid. The body builds its proteins almost entirely from the other (L) form, and D forms make peptides like hexarelin harder to break down.

Daily total

All the amounts given in one day, added together. For example, 100 mcg three times daily is a 300 mcg daily total.

Desensitization

When the body responds less to a substance after repeated doses. For hexarelin, the growth-hormone response to twice-daily injections was about 45% smaller after 16 weeks and recovered 4 weeks after stopping.

Dilated cardiomyopathy

A heart-muscle disease in which the main pumping chamber becomes enlarged and weak. A single hexarelin dose did not improve pumping in people with this condition.

Dose (amount each time)

The amount given on one occasion. A protocol lists both the dose and how often it is given.

ECG (electrocardiogram)

A recording of the heart's electrical activity, sometimes called a heart tracing. It can show rhythm changes such as a lengthened QT interval.

Ejection fraction

The share of blood that the heart's main pumping chamber pushes out with each beat. In healthy adults it is usually a little over half.

Freeze-dried (lyophilized)

Dried by freezing and removing the water, leaving a powder. Hexarelin is sold this way and mixed with liquid before use.

Ghrelin

A hormone made mainly in the stomach. It signals hunger and acts on the ghrelin receptor to trigger growth-hormone release.

Ghrelin receptor (GHS-R1a)

The receptor that ghrelin, hexarelin and similar peptides switch on. It is found in the brain, the pituitary gland and many other organs.

GHRH

Growth-hormone-releasing hormone, the brain's own signal telling the pituitary to release growth hormone. CJC-1295, sermorelin and tesamorelin are lab-made versions.

Growth hormone (GH)

A hormone released in bursts by the pituitary gland. It affects growth, metabolism and body composition, and prompts the body to make IGF-1.

Half-life

The time it takes for the level of a substance in the blood to fall by half. Hexarelin's half-life in people has not been published; it is not the same as how long an effect lasts.

HbA1c

A blood test that reflects average blood sugar over roughly the previous three months.

Hypothalamus

A small area at the base of the brain that controls the pituitary gland, hunger and several hormone systems.

IGF-1

Insulin-like growth factor 1, a hormone made mainly by the liver in response to growth hormone. A blood test for IGF-1 is the usual way to check growth-hormone activity.

Intranasal

Sprayed or dropped into the nose, to be absorbed through its lining.

Intravenous (IV)

Given directly into a vein, so it enters the bloodstream immediately. Most human hexarelin studies used a single IV test dose.

Investigational

Still being studied and not approved by a regulator, such as FDA, to treat any condition.

Lipoprotein(a)

A cholesterol-carrying particle in the blood. High levels are linked to a higher risk of heart disease, and levels are mostly set by genes.

Loading phase

A short period of higher doses at the start of a course. None of the hexarelin protocol sources reviewed for this guide describes one.

mcg and mg

Micrograms and milligrams. 1 mg equals 1,000 mcg. Hexarelin protocol amounts are usually written in mcg.

Oral

Taken by mouth and swallowed, as a tablet, capsule or liquid.

Peptide

A short chain of amino acids. Hexarelin is a chain of six.

Pharmacokinetics

How the body absorbs, moves, breaks down and removes a substance. For hexarelin, drug levels over time have been measured only in animals; one laboratory test measured its binding in human blood plasma.

Pituitary gland

A pea-sized gland at the base of the brain that releases growth hormone, prolactin, ACTH and several other hormones.

Placebo

A dummy treatment with no active ingredient, used as a comparison in studies.

Preclinical research

Studies done before or alongside research in people: cell studies and animal studies.

Prolactin

A pituitary hormone best known for milk production. Levels that stay high can affect periods, fertility, libido and breast tissue.

QT interval

A measurement on an ECG of how long the heart takes to recharge between beats. A lengthened (prolonged) QT interval can raise the risk of dangerous heart rhythms.

Reconstitution

Mixing a freeze-dried powder with a liquid so it can be measured and injected. The amount of liquid sets how much peptide each unit holds.

Research use only

A label on products sold for laboratory research. It does not mean a product is approved, tested for human use or legal to sell as a medicine.

Schedule 4 (Australia)

Australia's prescription-only medicine category. Hexarelin is also on a list of substances that are illegal to possess without authority.

Secretagogue

A substance that makes a gland release a hormone. A growth hormone secretagogue makes the pituitary release growth hormone rather than supplying it.

Slow-wave sleep

The deepest stage of sleep, when the body releases much of its daily growth hormone.

Somatostatin

A hormone from the brain and gut that switches growth-hormone release off. It works as a brake against GHRH and hexarelin.

Subcutaneous (SC)

Injected into the fatty layer just under the skin. This is the route most hexarelin protocol descriptions use.

Sublingual

Held under the tongue to be absorbed through the lining of the mouth. It has never been tested for hexarelin.

Syringe units

Markings on an insulin syringe that measure volume. On a U-100 syringe, 100 units equal 1 mL. The amount of drug per unit depends on the vial's concentration.

Titration

Adjusting a dose in steps, usually starting lower and increasing if needed.

WADA

The World Anti-Doping Agency, which publishes the list of substances banned in sport. It lists hexarelin under its official name, examorelin.

Withdrawal and rebound

Withdrawal effects are symptoms caused by stopping a substance. A rebound is a problem returning worse than before after stopping. Neither has been studied for hexarelin.

Explore more of the research

Go deeper into the preclinical experiments behind the claims.

Across this guide, the citations include 94 original scientific papers: 40 reports of human studies, 49 cell and animal studies and 5 anti-doping analysis papers. The library below summarizes 49 of the cell and animal papers, grouped by the question they address. Paper counts are not counts of independent research teams: a few groups published many of these studies. Regulatory documents, labels, registry searches, reviews, websites and personal accounts are counted separately.

Doses in animal studies are given per kilogram of body weight and cannot be converted into human doses. "Into the abdomen" (intraperitoneal) and "into the brain" (intracerebroventricular) are research routes used in animals, not people.

How this guide was researched

This guide is built from a thorough review of the sources cited throughout it: published scientific studies, a search of clinical-trial registries, regulatory documents, official labels of related medicines and published protocol descriptions. We also reviewed public online forums and community education groups where people describe their own experiences with hexarelin.

The guide cites 193 sources, including 94 original scientific papers. Each type of source answers a different question. Studies show what researchers measured. Protocol descriptions show how hexarelin is typically used. Personal accounts show what individual people experienced. Every numbered citation links to its entry below, labeled by source type.

How this guide was made

Research and drafting were AI-assisted. Every cited source was checked against the original, and the guide was reviewed and edited by Doserly before publication. It has not had an independent clinical review, and Doserly does not currently have medical reviewers. Doserly makes a medication and health-tracking app and runs Doserly Academy, both of which are promoted in this guide. Read our editorial policy for how guides are researched, updated and corrected.

This guide is for educational purposes. It summarizes what the reviewed sources report so the research is easier to understand; it is not medical advice. For a deeper dive, or to check any point for yourself, go straight to the cited sources.

Explore the sources