GHRP-2 (Pralmorelin): The Definitive Guide

What is GHRP-2?

GHRP-2 (growth hormone-releasing peptide-2), also called pralmorelin, is a lab-made peptide that makes the pituitary gland release a burst of growth hormone. In Japan it is a prescription diagnostic test, given once into a vein to check for growth-hormone deficiency. Elsewhere it is unapproved (investigational), and people inject it hoping for more muscle, less fat or better sleep. [1], [17], [18]

It is a chain of six amino acids. Three are in a mirror-image ("D") form that the body does not normally use, and one of those, D-2-naphthylalanine, is not among the 20 standard amino acids at all. It works by copying ghrelin, a hunger hormone made mainly in the stomach, at the ghrelin receptor. That receptor sits in the hypothalamus and the pituitary gland (a pea-sized gland at the base of the brain), and switching it on releases growth hormone. Because GHRP-2 makes the body release its own hormone rather than supplying it, it is called a growth hormone secretagogue. [19], [10], [1], [20]

GHRP-2 was made in 1992 in the laboratory of the American researcher Cyril Bowers, and it has several development names: KP-102 (Kaken Pharmaceutical, Japan) and GPA-748 (Wyeth, United States). Japan approved it in October 2004 as the diagnostic GHRP Kaken 100, on sale since February 2005. A Japanese nasal-spray version was tested as a growth treatment for children and failed its trial, and no country has approved GHRP-2 as a treatment. [6], [21], [1], [9], [2]

It is not growth hormone or a steroid, and it is not the same as GHRP-6, an older relative, or ipamorelin, a newer one, although all three act on the same receptor. [7], [22]

Typical GHRP-2 Protocols

The most common pattern in the reviewed sources is 100–300 mcg per injection, given one to three times a day on an empty stomach, for 8–12 weeks followed by about 4–8 weeks off. Once-a-day schedules usually put the injection at bedtime, and many sources pair GHRP-2 with CJC-1295 without DAC. [3], [23], [4], [24], [25], [26], [27], [28], [29], [18]

Titration Changing the amount in steps

The usual approach starts at 100 mcg once a day at bedtime and moves up, adding a morning injection or raising the amount, depending on response and tolerance. A group of near-identical pages keeps one injection a day and steps from 100 to 150 to 200 mcg over the first 8 weeks, with an optional 250–300 mcg later. Another starts at 100 mcg and adds 50 mcg every 3–7 days. [3], [23], [30], [31], [32]

Breaks and cycles

After 8–12 weeks, sources describe 4–8 weeks off before another course; one uses 8 weeks on and 4 off, another 4–8 weeks on and 2–4 off. Many also skip two days each week, written as 5 days on, 2 off. [3], [4], [24], [28], [29]

Read the units: mcg means micrograms; 1 mg equals 1,000 mcg. The amounts refer to GHRP-2 itself. In a blend, the vial total is not the GHRP-2 amount, so blend amounts have their own table below. A few pages write "100–300 mcg" as the whole day's total instead of the amount each time, a threefold difference; see where protocols differ.

Each row is a complete schedule as its source published it. Low, mid and high are alternatives, not steps to move through. These schedules come from protocol websites rather than clinical trials, and no controlled study has tested them. Longer records of repeated injections include an eight-month study of weight-based daily doses in six children and a clinic records review of men using a three-peptide mix; neither tested these schedules. [3], [5], [87], [36]

Before relying on any row: in a five-day study of daily 100 mcg injections in healthy men, the growth-hormone response shrank by about 40% within five days and IGF-1 did not rise. GHRP-2 raises hunger, prolactin and cortisol, and FDA lists reports of serious events, including higher insulin needs and pancreatitis, without an established cause. The approved product must not be used in pregnancy; people with pituitary tumours, diabetes or prediabetes have extra reason for caution, and under-18s have been studied only in diagnostic tests and growth trials. [5], [7], [10], [1] Research-market products are not checked by any regulator, and laboratories have found an altered version of GHRP-2 in a seized vial. A blend label may give the combined total rather than the GHRP-2 amount, which changes any syringe-unit conversion. GHRP-2 is banned in sport at all times. [33], [16] Full risks and who should be cautious.

What are the usual CJC-1295 and GHRP-2 amounts?

GHRP-2 is most often taken with CJC-1295 without DAC (a lab-made version of the brain's growth-hormone-releasing hormone, also sold as Mod GRF 1-29) or with sermorelin, a similar peptide, either in the same injection or bought premixed. The amounts below are per peptide. [24], [4], [34]

The three-peptide combination mirrors a US men's health clinic that prescribed 100 mcg each of GHRP-2, GHRP-6 and sermorelin three times a day; its results are in the human research section. [36] In community education groups, members more often meet GHRP-2 inside premixed vials of three or four peptides, where the GHRP-2 share can work out to 500 mcg or more per injection, well above these schedules. See where blends go wrong.

What doses have been tested in people?

The only approved dose is 100 mcg given once, slowly into a vein (intravenous), as a diagnostic test; children aged 4 to 17 receive 2 mcg per kilogram, up to 100 mcg. Research used single IV doses, 100 mcg injections once a day for five days, a 30-day pump and, in children, weight-based daily injections, nasal sprays and tablets; none tested 100–300 mcg two or three times a day for weeks. [1], [5], [37], [87] See every study dose.

What is GHRP-2 commonly used for?

People usually look into GHRP-2 because they hope more growth hormone will bring something they want: more muscle, less body fat, faster recovery from training or injury, better sleep or "anti-aging". A smaller group uses it on purpose to feel hungrier and eat more, for example to gain weight. Clinics and websites often describe it as a stronger option than ipamorelin. [3], [24], [48]

The honest summary is short. Its one approved use is a diagnostic test that checks whether the pituitary can release growth hormone. The one treatment tested in a proper trial, a nasal spray to help short children grow, did not beat placebo. None of the popular adult uses has been tested in a controlled human trial, and the one study of sleep found no benefit. What exists is a large body of short hormone studies in people, a few appetite studies, animal studies and personal accounts. [1], [6], [49]

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Where do the popular GHRP-2 claims come from?

“Raises growth hormone”

Human studies (IV)
Yes: one IV dose reliably raises growth hormone; this is the basis of the approved Japanese diagnostic test.

“Makes you hungry”

Human studies (infusion)
Yes: a 4.5-hour infusion raised food intake 36% in lean men; effect grew with dose.

“Helps children grow”

Randomized trial, 126 children
No: a 48-week nasal-spray trial found no difference from placebo in growth or IGF-1.

“Deeper sleep”

One human study, 7 men
No deep-sleep increase after a night-time IV dose.

“Builds muscle, burns fat”

Rats and mice
Less muscle breakdown in sick rats; mice gained fat, not lean mass. No human trial.

“Heals injuries”

One rat study
Better tendon-to-bone healing after rotator-cuff repair in rats. No human study.

“100–300 mcg, 1–3 times a day”

Dosing websites
Never tested as written; a 5-day study of 100 mcg once a day in healthy men saw the effect fade.

Of these claims, only growth-hormone release and appetite are supported by human studies; the one growth trial was negative.

Raising growth hormone and IGF-1

This is what GHRP-2 does most reliably in people. After a single 100 mcg dose into a vein, growth hormone peaks within an hour; in 77 healthy adults the average peak was about 85 micrograms per litre, many times the resting level. Researchers have described it as the most potent growth-hormone-releasing hexapeptide available for human study, and it released more growth hormone than a matching dose of GHRH. [50], [51], [52], [7]

Growth hormone in turn prompts the liver and other tissues to make IGF-1 (insulin-like growth factor 1), the blood test people use to check for a change. Whether IGF-1 rose depended on how GHRP-2 was given: not after five days of daily injections or 48 weeks of a nasal spray, but yes with a constant 30-day pump and in men injecting a three-peptide mix three times a day. [5], [6], [37], [36] See the studies.

A secretagogue only works if the pituitary can still make growth hormone. In people with severe growth-hormone deficiency, the average peak after the diagnostic dose was about 1.4 micrograms per litre, and adults whose GHRH receptor does not work had a much smaller response. [1], [53]

Muscle, strength and body composition

No human trial has tested GHRP-2 for muscle or strength. The clinic chart review above measured IGF-1 and sex hormones, not muscle, strength or body fat, and the one adult report that tracked muscle mass describes a single woman regaining weight after severe anorexia nervosa (see appetite). [36], [64]

The animal results are mixed. In rats with arthritis, burns or high-dose steroid treatment, GHRP-2 reduced the signals that break down muscle protein. In mice given daily injections, it increased fat and bone mass but not lean mass, and in mice unable to make GHRH it failed to raise growth hormone and worsened body composition. [54], [55], [56], [57], [58] People who report gains are usually also training, dieting and taking other compounds, often anabolic steroids. [59], [60]

Fat loss

No human study has tested GHRP-2 for fat loss. The appetite rise described below works against it, and in mice daily GHRP-2 added body fat. One short study in older men found a 60% rise in blood fatty acids soon after an IV dose, a sign that fat was being released, which says nothing about lasting fat loss. [57], [61]

Appetite and weight gain

GHRP-2 makes people hungry, and this is well measured. In seven lean men given a 4.5-hour subcutaneous infusion, every man ate more at a buffet, 36% more on average than on a salt-water placebo. In a second study of 19 lean and obese adults, the effect grew with the dose: 10% more food at the lower rate and 34% more at the higher. [8], [62]

Over months the picture is weaker. In ten children taking GHRP-2 tablets for a year, appetite rose for a while but body mass index did not change significantly. One woman with long-standing severe anorexia nervosa gained weight, from 21.1 to 27.8 kg, while using a nasal spray before meals for about a year; that is one case, with no comparison. [63], [64]

Some people use GHRP-2 deliberately to eat more, for example injecting 100 mcg half an hour before the first meal. In community education groups, a few members have considered it after losing weight on a GLP-1 medicine (a weight-loss drug such as semaglutide), without reporting how it went. [48], [65]

Sleep

Better sleep is a common hope, and the one controlled study found no support for it. In seven young men given GHRP-2 into a vein during the night, growth hormone and prolactin rose, but deep (slow-wave) sleep did not increase, and there was a slight, non-significant tendency to wake more in the next hour. Personal accounts go both ways (see them). [49]

Recovery and injuries

There is no human study of GHRP-2 for tendon, ligament, muscle or bone injury. In rats with a surgically repaired rotator-cuff tear, GHRP-2 improved healing of the tendon-to-bone attachment at 8 weeks, and in rats with arthritis it reduced joint swelling. [66], [67] Personal injury stories are hard to read: one person credited GHRP-2 and a GHRH peptide for a back strain that healed in two days, while also taking BPC-157. [68]

Helping short children grow: the tested treatment

This is the only use tested as a treatment in a randomized trial, and it failed. An early uncontrolled study of 15 short children using a nasal spray reported faster growth, but a later double-blind trial in 126 children with growth-hormone deficiency found no difference from placebo in growth or IGF-1. The controlled result is the one that counts. [69], [6] See the trial.

Diagnosing growth-hormone deficiency: the approved use

In Japan, doctors inject 100 mcg into a vein and measure growth hormone over the next hour. A peak of 15 ng/mL or less (9 ng/mL on tests calibrated to recombinant growth hormone) points to severe deficiency. In the validation study, the test clearly separated 58 adults with deficiency from 77 healthy adults, and in 71 adults with pituitary tumours it agreed well with the older insulin tolerance test (sensitivity 85.5%, specificity 94.5%). Because GHRP-2 also releases ACTH, researchers have tried the same test for checking the adrenal stress-hormone system, but in 254 patients it was not accurate enough for general use (sensitivity 64%, specificity 79%), though it did better in a subgroup of men. [1], [50], [70], [71]

Other uses you may come across

Hospital studies gave GHRP-2 infusions to critically ill adults (results), and heart, lung, liver and pain effects have been studied only in animals or cells. [72] Explore the animal research.

Where do GHRP-2 protocols differ?

The label dose, the study doses and the website doses answer different questions. The Japanese product asks whether the pituitary can release growth hormone after one IV dose. The research studies asked what happens over hours, days or, at most, a month. Protocol websites describe months of injections one to three times a day. Treating them as one "consensus dose" would erase route, population, duration and purpose. [1], [5], [3]

Is the number for one injection or the whole day?

The same "100–300 mcg" can mean very different amounts. Most pages mean it per injection, one to three times a day, which adds up to as much as 900 mcg a day. Once-a-day pages use the same numbers as the whole day's amount, and one page contradicts itself, listing "300 mcg daily" as its advanced level while its text describes two or three injections a day. In community education groups, one widely shared course card lists 100–300 mcg per day, split into up to three injections, so its injections are one third the size of most websites'. Clinicians interviewed for a 2021 review commissioned by FDA also spoke in daily totals, describing typical injected doses of 100–500 mcg a day. [25], [73], [29], [74]

Before comparing any two schedules, check whether each number is the dose (the amount each time) or the daily total.

Once, twice or three times a day?

All three appear, and three times a day is the most common upper limit (26 of 39 website rows). Sources favouring several injections point to GHRP-2's short half-life, measured at about 25–40 minutes after an IV dose, though many pages quote other figures. No study has compared one daily injection with several. [1], [75], [26]

Where timing is given, the usual slots are first thing in the morning, before or after training, and bedtime; one page adds at least 3 hours between injections. [28], [29]

Does it have to be taken on an empty stomach?

Nearly every source says so, and here there is some human support: the Japanese label requires fasting because eating changes growth-hormone results, the peak after GHRP-2 was higher in fasting men, and lowering blood fats with a drug enlarged the response in older men. [1], [76], [61]

How long to wait is not settled. In community education groups, advice ranges from 60–90 minutes to 2–3 hours after food, and from 20 to 60 minutes before the next meal. No study has tested these intervals.

Bedtime: better or worse for sleep?

Websites call the bedtime injection "the single most important", aiming to add to the body's largest natural growth-hormone release during early sleep. [3] Against this, the only controlled study found that GHRP-2 during the night did not deepen sleep, and some people report lying awake with a pounding heart after a bedtime dose. [49], [77], [78] In community education groups, one course recommends bedtime for once-daily use, while other educators advise moving the injection earlier if sleep suffers. Neither choice has been tested.

Do sources start low?

Many do, though fewer independent sources than it appears. A once-a-day ladder of 100, 150 and 200 mcg, with an optional 250–300 mcg later, appears on five pages with shared sentences, so it is one schedule repeated, not five confirmations. The same template appears on ipamorelin pages. [23], [30], [73], [31], [79]

What is the "saturation dose"?

Many pages say GHRP-2 reaches its maximum effect at about 1 mcg per kilogram of body weight, or 100 mcg, and that more only adds side effects. That rule of thumb traces to bodybuilding forum advice from the early 2010s, which personal accounts still cite. [3], [75], [80], [81]

Human studies do not show a ceiling at that dose. Given into a vein, 2 mcg per kilogram released more growth hormone than 1 mcg per kilogram, and in postmenopausal women the response kept rising across doses from 0.03 to 3 mcg per kilogram. No study has measured a dose-response for subcutaneous injections. Side effects rise with dose too: hunger in the appetite study grew from 10% to 34% more food as the dose went up. [7], [82], [62]

How long, and what happens between courses?

The course length most often given is 8–12 weeks, sometimes 16, with 4–8 weeks off, and many schedules skip two days each week. In community education groups, suggestions run from 4–6 weeks to 16 weeks, and some educators advise continuous use or rotating between ghrelin-receptor peptides. [3], [4], [24], [28]

Breaks are meant to stop the body getting used to GHRP-2, called desensitization. The human studies of repeated dosing point in different directions:

Doserly

What happened with repeated GHRP-2 in people?

Daily injections

100 mcg under the skin, once a day for 5 days · 9 young men

Average growth-hormone peak (µg/L)

Day 1

83

Day 3

59

Day 5

51

IGF-1 did not rise

Constant pump

1 mcg per kg per hour under the skin, for 30 days · 17 older adults

Growth-hormone release compared with saline (placebo = 1×)

Day 1

more than 3×

Day 14

more than 1.8×

Day 30

more than 1.8×

IGF-1 rose to a plateau

Pump values were reported only as “more than”. Neither study tested the 1–3 daily injections for weeks that websites describe.

Daily injections lost part of their effect within 5 days; a constant pump kept working for 30 days.

• Daily injections faded. In nine young men given 100 mcg once a day, the average growth-hormone peak fell from 83 to 59 to 51 micrograms per litre on days 1, 3 and 5, and IGF-1 did not rise. [5]
• A constant pump kept working. In 17 older adults, growth-hormone release stayed more than 1.8 times the placebo level on days 14 and 30, and IGF-1 stayed raised. [37]
• A long nasal course faded partly. In the children's trial, the peak response to the higher-dose spray fell from 26.4 to 14.6 ng/mL over 48 weeks. [6]

The patterns differ (separate injections versus a constant infusion, young versus older people), so neither result transfers to website schedules. No study has tested 5-days-on, 2-days-off schedules, 8-weeks-on, 4-weeks-off cycles or rotation. Several pages cite "the five-day study" for their breaks under the wrong authors; it is Nijland and colleagues, 1998, and it tested no breaks. [24], [3], [29], [5]

Should GHRP-2 be combined with CJC-1295 or another GHRH?

Most protocol sources treat the pairing as standard, reasoning that the two peptides press two different "release" switches on the pituitary (see how it works). One page says the pair produces two to three times the growth-hormone pulse of either peptide alone, citing "consistent user reports". [24], [3]

The human studies are more mixed. In eight healthy men given 1 mcg per kilogram of each into a vein, the combination released about as much growth hormone as the two added together: additive, not synergistic. Other studies found synergy, larger in younger people and smaller in those with more abdominal fat. No study has tested GHRP-2 with CJC-1295 by subcutaneous injection. [52], [83], [37] Read the Doserly guides to CJC-1295, sermorelin and tesamorelin.

Can it be combined with ipamorelin or GHRP-6?

Most sources say no, because the peptides use the same receptor. In rat pituitary cells, GHRP-2 and GHRP-6 together at full strength released no more growth hormone than either alone, and each blunted the cells' later response to the other. In community education groups, educators disagree, sometimes within the same course: some describe GHRP-2 with GHRP-6 or ipamorelin at lower doses, while most teach "one GHRH plus one GHRP". The US clinic in the men's study did combine GHRP-2 and GHRP-6. [24], [20], [36]

What about premixed blends?

Premixed vials tie the doses together. FDA noted in 2024 that CJC-1295 is sold in powders premixed with GHRP-2, and with GHRP-2 and ipamorelin. [34] In community education groups, members describe four-peptide vials in which a normal dose of the main ingredient delivers roughly 500–750 mcg of GHRP-2, and experienced members advised switching to single-peptide vials.

Blend charts can contain large arithmetic errors. One vendor's own guide for a four-peptide vial (5 mg GHRP-2, 5 mg tesamorelin, 2.5 mg ipamorelin and 0.5 mg MGF, 13 mg in all) assumes 2 mL of liquid and lists doses of 20 to 80 units. At that strength each unit holds 25 mcg of GHRP-2, so 20 units delivers 500 mcg and 80 units 2,000 mcg: about two to twenty times the usual 100–300 mcg. The same guide says each unit holds 0.65 mg of the blend; the correct figure is 0.065 mg, so its milligram doses do not match its unit counts. [47], [84]

One account describes two days of nausea after a 750 mcg blend dose. [85] See the Doserly guide to the CJC-1295 and ipamorelin blend.

How do micrograms convert to syringe units?

A U-100 insulin syringe has 100 units per millilitre, so units measure volume. How much GHRP-2 each unit holds depends on how much liquid was added to the vial.

For example, 5 mg (5,000 mcg) mixed into 2 mL gives 2,500 mcg per mL, or 25 mcg per unit. So 100 mcg is 4 units, 200 mcg is 8 units and 300 mcg is 12 units. Mixed into 3 mL instead, the same vial holds about 16.7 mcg per unit, so 100 mcg becomes 6 units. [24], [23]

The dose stays the same; only the unit count changes. Doserly's reconstitution calculator works this out for a single-peptide vial and shows each step; for a blend, it cannot split the vial into its ingredients. The arithmetic assumes the vial holds what its label says; it cannot check a product's strength, purity or sterility.

What happens when you stop GHRP-2?

This has not been studied. No study has looked for withdrawal effects or a rebound, or at how the hormone system recovers, after a course of GHRP-2, and none have been documented. That is missing data, not proof that none exist.

What is known is short-term. GHRP-2 clears from the blood within hours (its IV half-life is about 25–40 minutes), though breakdown products were found in urine for up to 47 hours after one nasal dose. In calves, the response to a second dose was still blunted when the doses were four hours apart, the longest gap tested, so how quickly it recovers is not known. In a small study of six children, growth was faster during GHRP-2 than before it or after it stopped, which suggests any effect ends with treatment. [1], [90], [91], [87]

Personal accounts add little. One person said hand numbness went away after stopping their peptides, and another described losing the feeling of fullness for more than 10 days after a five-month course of GHRP-2 and CJC-1295; neither can be checked. In community education groups, educators say no tapering is needed, without citing evidence. [92], [93]

Does GHRP-2 work the same by injection, nasal spray or by mouth?

No. GHRP-2 raises growth hormone by all three routes, but the amounts needed differ enormously, and only the IV route has been measured properly. Every human measurement of GHRP-2 in the blood (pharmacokinetics) comes from an intravenous dose, which puts the drug straight into a vein. [1], [94], [95]

• Subcutaneous injection. It works: single injections and a constant subcutaneous pump both raised growth hormone. How much of an injected dose reaches the blood (bioavailability) and how long it stays there have never been measured in people. [5], [37]
• Nasal spray. Intranasal GHRP-2 raised growth hormone in children at 5–20 mcg per kilogram, and in rats about half of a nasal dose reached the blood. In the children's trial, total growth-hormone exposure after a spray was more than ten times smaller than after a growth-hormone injection, which the authors suggest is why the children did not grow faster. [96], [97], [6]
• By mouth. Swallowed GHRP-2 also works, but at doses hundreds of times larger, such as 900 mcg per kilogram twice a day in children, and food reduces the effect. [63], [98], [6]

How long does GHRP-2 last in the body?

After an IV dose, GHRP-2's half-life was about 25–40 minutes in healthy adult men (0.42–0.69 hours) and about 33 minutes in children. The growth-hormone burst it triggers peaks 15–60 minutes after the dose; in children the average peak came at about 25 minutes. [1], [94]

Most of a dose is not found unchanged in urine: after 100 mcg into a vein, about 2% came out unchanged and about 4% as breakdown products within 24 hours, and the label concludes that most leaves through the bile, as in rats. [1], [99]

Half-life is not the same as how long any benefit lasts, and an IV half-life cannot be copied over to a subcutaneous injection, which is absorbed more slowly. Figures on dosing pages of "15–30 minutes" or "15–60 minutes" do not match any published measurement. [75], [26], [1]

Is pralmorelin hydrochloride different from GHRP-2?

It is the same peptide paired with hydrochloride, a salt form that makes it a stable powder. The Japanese medicine is pralmorelin dihydrochloride (molecular weight 890.9), while the peptide alone weighs 818.0. FDA's substance registry lists the two forms separately, and chemical databases give different registry (CAS) numbers for the salt, so a CAS number on a label is not a reliable identity check. [1], [17], [100], [101]

Look-alike molecules also exist. Anti-doping laboratories have found GHRP-2 with an extra amino acid (glycine) added at one end in seized vials and black-market products, apparently designed to avoid detection. [33], [102], [103]

Does the injection site matter, and should it be injected near an injury?

Dosing pages name fatty areas such as the belly, and no study has compared injection sites. [104] No study has tested injecting GHRP-2 near an injury. It works by acting on the brain and pituitary, which then release growth hormone into the whole bloodstream. FDA's concern about injected and nasal GHRP-2 is that the product itself may trigger an immune response. [1], [10]

How should GHRP-2 be stored, and how long does it last?

The only tested storage rules belong to the approved Japanese product, a single-use vial meant to be mixed and injected straight away. How long a mixed research vial keeps its strength over days or weeks has not been established. [1]

• The approved product. The freeze-dried powder (100 mcg of GHRP-2 with mannitol, an added sugar alcohol) is kept at 10 °C or below, must not be frozen, and has a 3-year shelf life. In the maker's tests, unopened vials kept dark at 10 °C stayed within specification for 36 months, while two months at 40 °C increased breakdown products and lowered the GHRP-2 content. Strong light broke down GHRP-2 in the bare glass vial but not in its original packaging, and the label says to keep it away from light once the outer box is opened. [1], [9]
• After mixing, per the label. The label specifies 10 mL of saline, added just before a single use, with the solution used as soon as possible. In the maker's test the solution was unchanged after 24 hours, at room temperature in room light or at 10 °C in the dark; the maker still asks for immediate use to protect sterility, not because the peptide breaks down. [1], [9]
• Research vials after mixing. No stability study of GHRP-2 reconstituted in bacteriostatic water was found. Supplier and dosing pages give anywhere from 14 to 30 days in the fridge, and none cites a test. Advice for the powder ranges from room temperature to freezing at −20 °C, which conflicts with the label's "do not freeze" for the finished product. [31], [30], [27], [4], [24], [28], [23]
• 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. One page warns never to use saline; the approved product is dissolved in saline, though for immediate use. [105], [27], [1]

This guide does not cover mixing or injection technique; the Academy note below covers practical handling.

What do we actually know about GHRP-2 in people?

More than for most research peptides, but not about the things people buy it for. Since the early 1990s, dozens of small human studies have used GHRP-2, mostly as a tool to probe the growth-hormone system for an hour or a day. Japan approved it as a diagnostic test on the strength of those studies. The one treatment tested in a large controlled trial failed, no trial has tested muscle, fat loss, recovery or aging, and the one sleep study found no deep-sleep gain. [1], [95], [6], [49]

What did the human studies find?

None of these studies tested the uses people buy GHRP-2 for, and none followed people on repeated doses for longer than about a year; most lasted hours, days or weeks. They were small, for most of them only the abstract was available to review, and several came from the same research groups or were run at the request of the manufacturer, as the children's growth trial was. [6]

What did the children's growth trial show?

This is the most rigorous test of GHRP-2 as a treatment. At 84 Japanese centres, 126 children aged 4 to 9 with growth-hormone deficiency were randomly assigned to a placebo spray or a lower or higher dose of GHRP-2 spray, twice daily for 48 weeks, with neither families nor doctors knowing who got what. [6]

Doserly

The 48-week children's growth trial

Nasal spray twice a day for 48 weeks · 126 children aged 4–9 with growth-hormone deficiency · randomized, double-blind, placebo-controlled

Growth-hormone peak after a spray at the start

ng/mL

Placebo (n=44)

4.5

Low dose (n=41)

13.2

High dose (n=41)

26.4

Growth rate during treatment (main outcome)

cm per year

Placebo (n=44)

5.4

Low dose (n=41)

5.2

High dose (n=41)

5.1

Height score change: +0.07 / +0.03 / +0.02 SD (placebo / low / high; no difference). IGF-1: no change in any group.

The spray raised growth hormone, but growth did not differ from placebo.

The spray did raise growth hormone after each dose (a peak of 13.2 and 26.4 ng/mL on the two doses at the start, against 4.5 on placebo). Yet the children grew at 5.1–5.2 cm a year on GHRP-2 and 5.4 cm on placebo, and IGF-1 did not change. The authors conclude that short bursts of the body's own growth hormone did not promote growth. [6]

Which study comes closest to how people use GHRP-2?

It is the 1998 five-day study of 100 mcg subcutaneous injections once a day in nine healthy young men. The growth-hormone peak fell by about 40% by day 5 and IGF-1 did not rise (details); osteocalcin, a marker of bone building, rose slightly. The study was short, had no placebo group and was reviewed from its abstract. It points to the body adapting quickly rather than to a growing effect. [5]

What did the clinic study in men show?

Of 105 men on testosterone prescribed the three-peptide mix at a US clinic, only 14 had records showing they took it consistently; in them, average IGF-1 rose from 159.5 to 239.0 ng/mL. The study did not measure muscle, fat, strength or blood sugar, had no comparison group and cannot separate the three peptides. [36]

What happened in critically ill patients?

One research group gave GHRP-2 into a vein for up to five days to men who had been critically ill for weeks. It restored growth-hormone release and IGF-1, but metabolic benefits appeared only when other releasing hormones were added, and with GHRP-2 alone, lactate (a marker of stressed metabolism) and white blood cells rose by day 5. FDA says it knows of deaths among critically ill study subjects given GHRP-2, without naming the study or establishing a cause; the group's study summaries we could read do not attribute any death to GHRP-2 (what FDA said). [72], [108], [109], [110], [10]

Are there registered GHRP-2 trials?

We found none for treatment. On September 24, 2026, ClinicalTrials.gov returned no studies for GHRP-2, GHRP2, pralmorelin, KP-102 or GPA-748, and the EU, UK and World Health Organization registries listed no GHRP-2 treatment trials (the World Health Organization search is a weak check). Japan's registries list three studies that use GHRP-2 only as a diagnostic test: two open university studies in people with hormone-producing pituitary tumours or Cushing's disease, still recruiting, and a completed study of pituitary hormone responses planned for 20 healthy adults. The Australian registry could not be searched. [111], [112], [113], [114]

A US study used a GHRP only as a research probe, and two EU-registered trials of once-weekly growth hormone in adults accepted a GHRP-2 test result as one way to confirm growth-hormone deficiency in Japan: a peak growth hormone of 9 ng/mL or less, the Japanese label's cutoff when the test is calibrated to recombinant growth hormone. [115], [116], [117], [1]

Does more growth hormone mean better health?

Not automatically. A growth-hormone burst, an IGF-1 number, a change in body composition and feeling better are four different outcomes. GHRP-2 reliably produces the first; the children's trial showed that repeated bursts did not deliver the outcome that mattered, growth. An IGF-1 result shows that growth-hormone signalling changed; it does not show that muscle, sleep or recovery improved, or that the change is safe. [6], [5]

How does GHRP-2 work?

GHRP-2 switches on the ghrelin receptor (also called GHS-R1a), the same receptor that the stomach hormone ghrelin uses. The Japanese label says it acts mainly through the hypothalamus, the brain area that controls the pituitary, and in rat experiments its effect shrank when that area was damaged. It also acts directly on the growth-hormone-making cells of the pituitary: in rat pituitary cells grown in a dish (cell study), it released growth hormone on its own. [1], [19], [20]

It needs a working GHRH system for its full effect. In adults whose GHRH receptor does not work because of an inherited mutation, GHRP-2 raised growth hormone 4.5-fold, against 79-fold in healthy people. It also resists somatostatin, the brain's "off switch" for growth hormone, better than GHRH does, which may be why it works so strongly in awake animals. [53], [19]

Why is it paired with a GHRH peptide?

The pituitary has two main "release" switches. GHRH (growth-hormone-releasing hormone) presses one; ghrelin, and GHRP-2, press the other. Because they use different receptors, using up one does not blunt the other: in sheep and rat pituitary cells and in calves, a first dose of GHRP-2 weakened the response to a second GHRP-2 dose but not to GHRH. That is the logic behind combining GHRP-2 with CJC-1295 or sermorelin (what the human studies found). [118], [20], [91]

Why does it raise cortisol and prolactin?

GHRP-2 is not selective for growth hormone. In healthy young adults, IV doses of 1 or 2 mcg per kilogram raised prolactin (the milk-production hormone) and ACTH and cortisol (the stress-hormone chain). The cortisol rise was similar to a standard stress-hormone test, and the prolactin rise was smaller than a standard prolactin test. In 42 men, peak cortisol reached 616 nmol/L after GHRP-2 against 420 after salt water. In rats, the ACTH release runs mainly through a brain signal (CRF) rather than a direct pituitary effect. [7], [119], [107], [120]

These rises were measured after single doses. During a 24-hour infusion, prolactin and cortisol rose only slightly, and in intensive care, cortisol did not change over several days. Months of several daily injections have not been studied. [51], [121], [108]

Is GHRP-2 stronger than ipamorelin or GHRP-6?

It depends on what "stronger" means. Potency is how small a dose is needed; maximum effect is the most growth hormone any dose can release. In pigs, GHRP-2 needed the smallest dose of the three to release growth hormone (0.6 against 2.3 for ipamorelin and 3.9 for GHRP-6, in nanomoles per kilogram) but reached the lowest maximum (56 against 65 and 74 ng/mL). In sheep pituitary cells, it was about ten times more potent than GHRP-6. In people, it released about as much growth hormone as hexarelin, another relative. [22], [118], [7]

So the common description of GHRP-2 as sitting "between GHRP-6 and ipamorelin" in strength, which Doserly's earlier page also used, is not accurate: per dose it was the most potent of the three in the studies that compared them. We found no human study that compared it directly with ipamorelin or GHRP-6. [22]

Why does it make people hungry?

Because ghrelin's other job is to signal hunger, and GHRP-2 copies it. Injected into the brains of rats, GHRP-2 made them eat more, and in mice given daily injections it raised food intake and fat mass through appetite-controlling signals in the hypothalamus. The human appetite results are under common uses. [122], [57]

Does the body get used to it?

To some extent. In pigs, IV doses two hours apart gave shrinking responses, while one daily injection kept working for 30 days with some fading; in calves, a second dose within four hours was blunted. In rat pituitary cells, IGF-1, which growth hormone triggers, reduced production of ghrelin receptors, a built-in brake. The human results are under how long, and what happens between courses. [123], [91], [124]

What do animal studies suggest beyond growth hormone?

In animals, GHRP-2 reduced muscle breakdown, protected heart muscle, reduced lung and liver injury and helped a repaired tendon heal, but it did not reduce artery plaque or restore growth without GHRH. None of these effects has been tested in people. [54], [125], [126], [127], [128], [129], [130], [66], [131], [58] Explore the animal research.

What are the risks and unanswered questions?

Is GHRP-2 safe?

As a single supervised diagnostic dose, its short-term side effects are known and mostly mild, and none was serious in the Japanese trials. For repeated self-injection, its safety has not been established. The longest controlled studies lasted 30 days by pump and 48 weeks by nasal spray in children, and none was large or long enough to detect rare or slow-developing harms. [1], [9], [37], [6]

There are no human data on cancer, pregnancy outcomes, antibodies against the drug or long-term heart and metabolic effects, and FDA lists reports of serious events whose cause has not been established. Short, small studies can miss uncommon problems and anything that takes months to appear. [10], [18]

What side effects appear in the label and trials?

For the single IV test dose, the Japanese label and the maker's detailed product document give these adverse reactions: [1], [9]

• How often: before approval, 86 of 227 people tested (38%) had at least one reaction. Most were mild and brief, and none was serious. A later survey of 503 patients recorded none.
• Most common: stomach rumbling (borborygmi, 11%), a warm or hot feeling (16.0% on the label), sweating (5%) and a raised white blood cell count.
• Less common: low blood pressure, nausea, stomach discomfort, sleepiness, dizziness, headache, flushing, cold sweat, hunger, tiredness, a bitter taste and a rise in the liver enzyme ALT.

In the 48-week children's trial, stomach rumbling in three children, and a nosebleed, low blood pressure and raised eosinophils in one child, were judged possibly related. In six children treated for eight months, no side effects or toxic effects were seen, and in the 30-day pump study "safety screening tests remained normal". In critically ill men, lactate and white blood cells rose by the fifth day of GHRP-2 alone. [6], [87], [37], [72]

Personal accounts add hunger, flushing and a pounding heart after the first injections, water retention, numb or aching hands, tiredness and disturbed sleep, mostly with a GHRH peptide in the same syringe. [132], [133], [92], [65], [78] Read the accounts.

What has FDA said about GHRP-2's risks?

In September 2023, FDA placed injected and nasal GHRP-2 on its list of compounding ingredients that may present significant safety risks. It gave three reasons: injected peptide products can trigger immune reactions, especially if the peptide clumps (aggregation) or contains impurities; GHRP-2's unnatural amino acid makes the product harder to characterize; and FDA is aware of reports of serious adverse events in people who received GHRP-2, "including increased insulin requirement to maintain the blood glucose level, death of critically ill study subjects, infection and pancreatitis, though causality has not been established". [10]

FDA does not name these reports, but two sets of public records fit its wording. One is a series of studies that gave GHRP-2 by IV drip to adults who had been in intensive care for weeks; the summaries we could read report hormone changes and blame no death or infection on GHRP-2. The other is FDA's adverse event database, which holds four 2016 reports naming GHRP-2, all for a compounded mixture of sermorelin, GHRP-2 and GHRP-6: one hospital stay for acute pancreatitis, two cases of hives, and burning pain with fever. A report about a mixture cannot show which ingredient, if any, was responsible. [72], [109], [110], [11]

Does GHRP-2 raise blood sugar?

It might, and no study has tested it properly. FDA lists reports of people needing more insulin to control their blood sugar. Soon after an IV dose, blood fatty acids rose by 60% in older men, and extra growth hormone can make the body less responsive to insulin. A review of the whole drug class notes concern about rising blood sugar from reduced insulin sensitivity. No controlled study has measured blood sugar or HbA1c during repeated GHRP-2 use, and the men's clinic study did not check them. In a rabbit model of long critical illness, four days of GHRP-2 with another releasing hormone did not change blood sugar or insulin needs compared with salt water. [10], [61], [134], [36], [135]

Some course material in community education groups says GHRP-2 improves insulin sensitivity; we found no study showing that. Several people describe shaky, sweaty, "hypoglycemic" spells soon after injecting, but none had their blood sugar measured. [136], [137]

Do the cortisol and prolactin rises matter?

After single doses the rises are modest, and whether months of injections keep cortisol or prolactin raised has not been studied (why it raises them). Some dosing pages warn of breast growth or sexual problems from prolactin; no GHRP-2 study has reported them. [7], [4]

A 2026 review for doctors notes that mildly raised prolactin or cortisol in someone using these peptides may come from the peptide, and suggests repeating the test after a break before ordering pituitary scans. [18]

Can GHRP-2 cause an allergic or immune reaction?

It is possible, and it is FDA's main stated concern for injected and nasal GHRP-2. Health Canada warns that unauthorized injectable peptides may cause infection and allergic reactions. [10], [12]

Personal accounts describe itchy red lumps at the injection site that shrank with later doses. [138], [80] In community education groups, one member described a delayed whole-body reaction, with hives and swelling around the eyes and throat, that they blamed on another peptide and an unnamed GHRP taken together. Swelling of the face, eyes or tongue, or difficulty breathing, can be signs of anaphylaxis, a severe allergic reaction that needs emergency care right away.

Does GHRP-2 cause cancer?

Nobody knows. There are no human or animal cancer studies of GHRP-2. The concern is theoretical: growth hormone and IGF-1 encourage cells to grow, and a 2026 review describes this as a possible risk for the whole group of growth-hormone-raising peptides, with no established cancer signal. [18]

A related, specific warning exists. The Japanese label notes that when similar drugs were given to people with pituitary tumours, some developed pituitary apoplexy, a sudden bleed into the tumour causing headache, vomiting and vision problems. [1]

Could product quality change the risk?

Yes. Outside Japan, there is no approved GHRP-2 product. Products are compounded or sold under "research use only" labels, and that label does not make a product suitable for human use. FDA does not review compounded drugs for safety, effectiveness or quality before they are sold. [139]

Laboratories have found GHRP-2 hidden in tablets sold as a nutritional supplement, and GHRP-2 with an added amino acid in seized vials and black-market products. FDA points out that GHRP-2's unnatural amino acid makes product identity harder to confirm. [140], [33], [103], [10]

Is GHRP-2 legal? Is it FDA-approved?

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

United States. GHRP-2 is not an FDA-approved medicine, and no approved product contains it. The recent steps:

• 2018 to 2020. FDA warning letters to five compounding pharmacies said GHRP-2 did not qualify for the rules that let pharmacies compound it; four of them name it among the pharmacy's compounded products. [141], [142], [143], [144], [145]
• September 29, 2023. FDA placed GHRP-2 for injection and nasal use in "Category 2" for outsourcing facilities (larger-scale compounders): substances that may present significant safety risks. It is still there. [10], [146]
• 2021. A university review for FDA of the compounding nomination (tablets, capsules, sprays and injections, including a mix with GHRP-6 and sermorelin) found no approved product in those forms. It left out safety studies, so it is not the source of FDA's list of serious events. [74]
• Now. On FDA's list for ordinary compounding pharmacies, updated May 14, 2026, GHRP-2 sits in "Category 3", nominated without adequate support. FDA noted in December 2024 that premixed CJC-1295 and GHRP-2 products are on the market. [147], [34]

Canada. Health Canada has not authorized GHRP-2, and its drug product database lists no product containing it. Its August 2025 advisory lists "GHRP 2" among seized unauthorized injectable peptides, notes that injectable peptides are regulated as prescription drugs and says selling unauthorized drugs is illegal. [12], [148]

Australia. Pralmorelin (GHRP-2) is a prescription-only medicine (Schedule 4) and is also listed among substances that are illegal to possess without authority, such as a legal prescription. [15]

Japan. GHRP Kaken 100 is an approved prescription medicine, but only as a single-dose diagnostic test given by a doctor. It was approved in 2004 and passed Japan's standard post-marketing re-examination in 2014. [1], [9]

European Union. No GHRP-2 medicine has been approved or assessed through the EU-wide process: the European Medicines Agency's full list of medicines has no entry for it. We did not check approvals by individual EU countries. [13]

United Kingdom. GHRP-2 is not a controlled drug: UK drug laws list growth hormone (somatropin) and HCG, but not GHRP-2, and we found no UK regulator notice naming it. We could not search the UK's database of licensed medicines, and not being controlled does not make selling it for human use legal. [14], [149], [150]

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

Is GHRP-2 banned in sport? Does it show up on a drug test?

Yes, it is banned. The World Anti-Doping Agency names "GHRP-2 (pralmorelin)" in section S2.2.4 of its Prohibited List, prohibited in and out of competition on both the 2026 list and the 2027 list that takes effect on January 1, 2027. The US Department of Defense also lists peptide hormones such as GHRP-2 among dietary supplement ingredients prohibited for military members. [16], [151], [152]

It is detectable. Anti-doping laboratories test urine for GHRP-2 and its main breakdown product, and an athlete has been sanctioned for using and possessing it. In one volunteer, traces were found in urine up to 47 hours after a nasal dose; no reliable detection window has been published for injections. GHRP-2 can also interfere with one type of growth-hormone doping test. [153], [154], [90], [155], [156]

Who should be especially cautious?

These groups have no safety data for repeated use. That is a reason for caution, not proof of harm.

• Pregnancy and breastfeeding. The approved product must not be used in pregnancy, and in rats GHRP-2 passed into breast milk. [1]
• Pituitary tumours. Similar drugs have been linked to pituitary apoplexy in people with pituitary tumours. [1]
• Diabetes, prediabetes or insulin resistance. Because of FDA's reports of higher insulin needs. [10]
• A history of cancer. Because of the theoretical growth-hormone and IGF-1 concern. [18]
• People trying to lose weight, or with a history of binge eating. GHRP-2 reliably increases hunger, and some people stop it for that reason. [62], [157]
• Under 18. Children have received GHRP-2 only in diagnostic tests and growth trials under specialist care, and the label notes that no clinical trial included children under 4, although the maker's survey of routine diagnostic use included children from 11 months old. This guide is written for adults. [1], [9]
• Competitive athletes and military members. It is banned. [16], [152]
• People taking other medicines. Interactions have not been studied; see the next question.

Has GHRP-2 been tested alongside other medicines?

Only in research settings, where it was combined with other releasing hormones and sex hormones, and a short course of the steroid prednisone reduced its growth-hormone effect. The Japanese label notes no experience giving it with other hormone tests such as CRH, LH-RH or TRH. Nothing has been published on GLP-1 medicines, insulin or other diabetes medicines, even though accounts combine GHRP-2 with weight-loss drugs. Bring a complete list of everything you take to a pharmacist or doctor. [72], [82], [107], [158], [1], [159]

What should be monitored while using GHRP-2?

There is no official monitoring plan for repeated use, because no regulator has approved GHRP-2 as a treatment. What exists is the approved test procedure, what the human studies measured, and what doctors writing about these peptides suggest. It can help you prepare questions for a clinician; it is not a personal testing plan. [1], [18]

What does the approved test involve?

The Japanese label covers a single dose, not a course. The person fasts and lies at rest before the dose, because food, stress and exercise change growth-hormone results; blood is then taken before the dose and at 15, 30, 45 and 60 minutes. Staff are told to watch for the listed side effects and stop or treat as needed. [1]

What did the human studies check?

• Hormones. Growth hormone, IGF-1 and its binding proteins, prolactin, ACTH, cortisol and, in some studies, thyroid-stimulating hormone. [37], [7], [53]
• Metabolism. Blood fatty acids, and in critically ill patients lactate and white blood cells. [61], [72]
• Blood pressure and fluid balance. After a 100 mcg IV dose in ten healthy men, blood pressure, blood concentration (hematocrit) and the water-balance hormone vasopressin did not change. [76]
• General safety tests. The 30-day pump study reported that "safety screening tests remained normal", without listing them in its abstract. [37]
• What was not reported. No published GHRP-2 study we found reports antibodies against the drug, heart tracings (ECGs) during repeated use, or blood sugar and HbA1c over weeks of injections. Not reported does not mean not measured, but there are no results to go on.

What do doctors and related-drug labels suggest?

These are class-based considerations for medicines that raise growth hormone or act on the same receptor, not GHRP-2 findings or a testing schedule.

• A 2026 review for doctors suggests checking fasting blood sugar or HbA1c in anyone using these peptides, and repeating a mildly high prolactin or cortisol result after a break before investigating the pituitary. [18]
• Macimorelin, an approved US diagnostic that acts on the same receptor and is swallowed once: it lengthens the QT interval (a measure of the heart's electrical recharge) by about 11 milliseconds, and its label warns against combining it with other drugs that do the same. [160]

Which signals matter, and why?

Every row comes from the studies, FDA's listing, the label and the accounts cited above. [10], [134], [5], [7], [62], [49], [1], [132], [92]

A single IGF-1 or prolactin result is hard to read without a starting value. In community education groups, the more careful courses advise testing IGF-1, blood sugar and HbA1c before starting and during a course, and cortisol and prolactin with longer use. No study has tested any testing schedule, so any testing is worth discussing with a clinician.

What do people in public communities report?

GHRP-2 is a minor topic next to ipamorelin. In the community education groups we reviewed, courses still teach it as a stronger "step up" from ipamorelin, but few members described using it, and those who did mostly described quitting because of hunger. In the public forum accounts we reviewed, most involve a GHRH peptide in the same injection (CJC-1295, often sold as Mod GRF 1-29, or sermorelin), and many also involve anabolic steroids, BPC-157 or weight-loss drugs. What follows are experiences with GHRP-2-containing routines, not effects that can be pinned on GHRP-2. [59], [132], [80]

How strong is the hunger, and does it last?

Hunger is the most consistent report, and it can start within minutes: one person described it arriving one to three minutes after an injection. Some people stopped because of it, one because they were still trying to lose weight. [48], [157], [161]

Timing seems to matter to some. One person had no hunger from a fasted morning injection but strong hunger from one taken two hours before dinner. Others say the hunger faded, within a week for one person and over a couple of months for another, and a few felt little or none, even at 300–500 mcg; one person on a three-peptide blend lost their appetite instead. One person taking the weight-loss drug retatrutide found GHRP-2 far hungrier than GHRP-6, the opposite of the usual ranking. [162], [163], [136], [164], [165], [166], [167], [159]

In community education groups, the members who described using GHRP-2 themselves named constant hunger as the reason they quit, and moved to CJC-1295 with ipamorelin.

What do the positive reports look like?

They are few and mixed with other changes. One person with a mildly underactive thyroid, taking 150 mcg once a day, felt better overall, with more energy. Another, after a month of GHRP-2 and CJC-1295, reported better workouts and some lean mass, with strong hunger, acne and irritability. A third, on 300 mcg at night with a long-acting CJC-1295, described great sleep and easing knee pain in the first week, along with low daytime energy and a suspected overdose from measuring with the wrong syringe. [168], [59], [169]

What happens after the first injections?

Several people describe a strong reaction soon after an early dose, often settling with later ones: flushing, heat, sweating, weakness, shaking and panic within minutes, with extreme hunger; or, 30 minutes after 125 mcg of GHRP-2 with 100 mcg of CJC-1295, pale skin, sweating, a pounding heart and shakiness they called "hypoglycemic". Another had flushing and a racing heart for about three minutes after a second dose. Nobody measured their blood sugar, and the first person thought they may have hit a vein. [132], [136], [170], [171]

These overlap with the diagnostic label's list: a warm feeling, sweating, cold sweat, hunger and unsteadiness. [1]

Can it make sleep worse?

Yes, for some people, and better for others. After 100 mcg each of CJC-1295 and GHRP-2 at bedtime, one person had a pounding heart, sweating and about four hours of sleep. Another, on 100 mcg of each twice a day, took hours to fall asleep and woke many times, and moving the injections to the morning did not help. A third, on 100 mcg of GHRP-2 alone twice a day, felt dizzy, sleepy and drained all day by day three. Some say the poor sleep lasted a week or two, and others describe the best sleep of their lives. [77], [78], [65], [172], [173], [138]

What other unwanted effects come up?

• Water retention and bloating: puffy hands after about six months of GHRP-2, "pretty noticeable" water retention with tesamorelin and GHRP-2, and water weight in the first week that settled in the second. Two people with bloating or swelling switched to ipamorelin or a CJC-1295 and ipamorelin routine. [133], [174], [170], [137], [175]
• Numb hands and wrist pain: constant pins and needles on a doctor-prescribed sermorelin and GHRP-2 vial in 2014, hands and forearms numb on waking after about three months, and carpal-tunnel-like wrist pain at three injections a day. [92], [176], [177], [170]
• Heart: a fast or irregular heartbeat. One person's palpitations went away during a week off, came back the day they restarted and again with a new batch, so they stopped. [178], [179]
• Skin: acne, and itchy lumps at the injection site; one person's rash and reactions stopped after changing both the peptide supplier and the mixing water. [59], [138], [180]
• After a very large dose: two days of no appetite and nausea after a 750 mcg dose of a three-peptide blend and a binge meal. [85]

A 2026 medical review lists swelling, numbness and joint pain as possible effects of growth-hormone-raising peptides as a group, and advises doctors to rule out other causes first. A single report cannot show which ingredient caused them. [18]

Does everyone notice a difference?

No. People describe little help with a soft-tissue injury, "not much improvement in the gym" on three injections a day, and side effects without the expected hunger. [138], [137], [65] In community education groups, no member shared GHRP-2 blood results such as IGF-1, so there is no way to tell who responded hormonally.

What do community education groups teach?

Courses present GHRP-2 as a standard option, most often 100–300 mcg two or three times a day with CJC-1295, sermorelin or tesamorelin, taken fasted. Educators disagree about whether it raises cortisol more or less than GHRP-6 (we found no human study comparing them) and about the points covered in where protocols differ. Some courses recommend it to athletes without mentioning that it is banned in sport.

How can you judge a GHRP-2 story?

Ask what exactly was taken and how much (GHRP-2 alone, with a GHRH peptide or in a blend; per injection or per day), what else changed (steroids, BPC-157, a GLP-1 medicine, diet, training), whether blood tests were done before and during use, and what happened later. A blend story cannot tell you which peptide did what.

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

All five act on the same ghrelin receptor. CJC-1295, sermorelin and tesamorelin work through the GHRH receptor instead and are the peptides most often combined with GHRP-2. Schedules for these research peptides come from protocol sources, not tested doses.

MK-677 is swallowed; the peptides are mostly injected, though GHRP-2 has also been tested as a nasal spray and tablets. GHRP-2 is the only one of the five with an approved medical use anywhere, as a diagnostic test, and it has many short human hormone studies. No study has compared any of them for muscle, fat, sleep or safety in people, so the table cannot say which works better. [1], [2], [6], [63] See also the Doserly guides to CJC-1295, sermorelin and tesamorelin.

Common questions about GHRP-2

How long does GHRP-2 take to work?

There is no established timeline for any felt benefit. Growth hormone peaks within an hour of a dose and hunger can start within minutes, but those are short-term effects, not results. IGF-1 did not rise after five days of daily injections, and personal accounts of sleep, energy or body changes range from the first week to never. [1], [5], [48] See what people reported.

Is GHRP-2 FDA-approved, and is it legal to buy?

It is not FDA-approved, and whether it can be bought legally depends on the country. Japan approves it only as a diagnostic test. FDA lists injected and nasal GHRP-2 among compounding ingredients that may present significant safety risks, Canada has not authorized it, Australia makes it prescription-only, there is no EU-wide approval, and in the UK it is not a controlled drug, which does not make selling it legal. [1], [10], [12], [15], [13], [14] See the dated legal-status summary.

Is 100 to 300 mcg a clinical dose?

No. It is the most common range on protocol websites, not a schedule tested in a trial. The approved adult dose, 100 mcg, is given once into a vein as a diagnostic test, and a five-day study of daily injections in healthy men used 100 mcg once a day. [3], [1], [5] See typical protocols.

Does GHRP-2 have to be combined with CJC-1295 no DAC?

No. GHRP-2 releases growth hormone strongly on its own. Adding a GHRH peptide releases more, but in one study of healthy men the effects simply added together, and the pairing has never been tested by subcutaneous injection. [52], [37] See combining with a GHRH.

Is GHRP-2 milder than GHRP-6 and stronger than ipamorelin?

Not exactly. Per dose, GHRP-2 was more potent than both in pigs, but reached a lower maximum growth-hormone level, and it raised cortisol like GHRP-6 while ipamorelin did not. We found no human study comparing their side effects directly. Personal accounts usually rank GHRP-6 as the hungrier of the two, though not always. [22], [166], [159] See is it stronger?

Does GHRP-2 make you hungry?

Usually, yes. In lean men, a GHRP-2 infusion made every participant eat more, 36% more on average. Personal accounts describe hunger within minutes; some use it deliberately, others stop because of it, and a few say it fades after a few days. [8], [157], [163] See appetite.

Is GHRP-2 a steroid, or is it growth hormone?

Neither. It is a six-amino-acid peptide that prompts the body to release its own growth hormone. Growth hormone itself is a much larger protein sold as prescription medicines, and anabolic steroids are a different kind of molecule altogether. It is still banned in sport. [17], [1], [16]

Can GHRP-2 be used long term?

Long-term use of the injections has not been properly studied. The longest adult study with a comparison lasted 30 days, using a pump; daily injections began losing effect within five days; and 48 weeks of a nasal spray in children brought no benefit. Most protocol sources cycle it for 8–12 weeks with breaks, and long-term questions about blood sugar, hormones and cancer risk are unanswered. [37], [5], [6], [3] See risks.

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. GHRP-2 raises both for a short time after a dose.

Adverse event

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

Aggregation

Peptide molecules clumping together in a product. Clumps can make a peptide less effective and more likely to trigger an immune reaction.

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 pigs. It shows what a substance does in a living body, but results in people can differ.

Bioavailability

How much of a dose reaches the bloodstream in a usable form. It depends heavily on the route and has not been measured for GHRP-2 in people.

Blend

A product that combines GHRP-2 with other peptides, such as CJC-1295 or sermorelin, in one vial. The blend's total amount is not its GHRP-2 amount.

Borborygmi

Rumbling or gurgling sounds from the stomach and intestines. It is one of the more common reactions to the GHRP-2 diagnostic dose.

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 GHRP-2; 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. Randomly assigning people to each group makes the comparison fairer.

Course and cycle

A course is the period of repeated use, such as 8 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 GHRP-2 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 GHRP-2, the growth-hormone response to daily injections shrank within five days in one study.

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.

Freeze-dried (lyophilized)

Dried by freezing and removing the water, leaving a powder. GHRP-2 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, GHRP-2 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.

GLP-1 medicine

A drug that copies the gut hormone glucagon-like peptide-1 (GLP-1), used for diabetes or weight loss, such as semaglutide or tirzepatide.

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.

Growth-hormone stimulation test

A test in which a doctor gives a substance that should make the pituitary release growth hormone, then measures how much appears in the blood. A low result points to growth-hormone deficiency. GHRP-2 is approved in Japan for this test.

Half-life

The time it takes for the level of a substance in the blood to fall by half. For GHRP-2 given into a vein it is about 25–40 minutes. 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 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. The approved GHRP-2 test is given this way.

Investigational

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

mcg and mg

Micrograms and milligrams. 1 mg equals 1,000 mcg. GHRP-2 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. GHRP-2 is a chain of six.

Pharmacokinetics

How the body absorbs, moves, breaks down and removes a substance.

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. GHRP-2 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.

Sermorelin

A lab-made copy of the first 29 building blocks of GHRH. It is often combined with GHRP-2.

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 GHRP-2.

Subcutaneous (SC)

Injected into the fatty layer just under the skin. This is the route most GHRP-2 protocol descriptions use.

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.

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 GHRP-2.

Explore more of the research

Go deeper into the preclinical experiments behind the claims.

Across this guide, the citations include 77 original scientific papers: 33 reports of human studies, 34 cell and animal studies and 10 anti-doping and product-analysis papers. The library below summarizes 33 of the cell, animal and analysis papers, grouped by the question they address. Paper counts are not counts of independent research teams: a few groups published many of these studies. Labels, regulatory documents, registry records, reviews, websites and personal accounts are counted separately.

In the route details, "into the brain's fluid spaces" (intracerebroventricular) and "into the abdominal cavity" (intraperitoneal) 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: the Japanese product label, published scientific studies, registered clinical-trial records, regulatory documents and published protocol descriptions. We also reviewed public online forums and community education groups where people describe their own experiences with GHRP-2.

The guide cites 189 sources, including 77 original scientific papers. Each type of source answers a different question. The label shows how the approved diagnostic is used. Studies show what researchers measured. Protocol descriptions show how GHRP-2 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