Semax: The Definitive Guide

What is Semax?

Semax is a lab-made peptide, a short chain of seven amino acids, sold in Russia as a prescription nasal-drop medicine for stroke, memory and thinking problems caused by poor blood flow in the brain, and some eye-nerve diseases. Online it is popular as a "focus" or nootropic peptide. [1], [2], [3]

It was developed in the early 1980s at the Institute of Molecular Genetics in Moscow from a short piece of ACTH, the pituitary hormone that tells the adrenal glands to release cortisol. The developers took the four-amino-acid piece linked to learning in animal studies and added three more (Pro-Gly-Pro) to make it last longer. The result, Met-Glu-His-Phe-Pro-Gly-Pro (MEHFPGP), is often called an "ACTH(4-10) analog". In animal tests it did not act like the hormone, although one human study found cortisol higher (see how it might work). [4], [5], [6], [7], [8]

Semax is a registered medicine in Russia (0.1% nasal drops since 1994, according to the manufacturer, and a stronger 1% form for stroke) and investigational elsewhere: it is not approved by the US Food and Drug Administration (FDA), we found no approval in other countries we checked, and its human research is almost entirely Russian. [6], [1], [7]

Typical Semax Protocols

On the label, each 0.1% dose is 2–3 drops in each nostril (200–300 mcg); how often and for how long depend on the use, from 2–3 times a day for 3–5 days to 4 times a day for 10–14 days. The 1% stroke doses are much larger and given alongside standard stroke care. The label also covers recovery after head injury or brain surgery and a children's schedule from age 7 under medical care, not repeated here. [1], [2]

What doses do research nasal sprays use?

Outside Russia, most people use a spray mixed from a research-grade powder, not the licensed drops. These schedules come from protocol websites.

The most common pattern in the reviewed sources is 200–600 mcg a day as a nasal spray, taken once in the morning or split into two or three sprays earlier in the day, for about 2 weeks. [14], [3], [15], [16]

What doses are used for Semax injections?

For injections, the recurring pattern is 200–500 mcg once a day, usually in the morning, for about 2 weeks, with some pages going to 1,000 mcg. [14], [13], [11], [17], [19]

Read these cautions before the numbers. Human studies gave Semax only through the nose, mostly at label-range doses in Russian patients, plus a few brief studies in healthy volunteers; the spray and injection schedules come from protocol websites, not trials. [1], [7]

• Do not stop or cut back prescribed medicine to try Semax. That includes ADHD stimulants, antidepressants and mood stabilisers. Semax has never been tested as a replacement for any of them, and in rodents it strengthened amphetamine's effects. In community education groups, some people describe making these changes without their prescriber. [7]
• The label rules it out with anxiety disorders, a history of seizures, acute psychiatric illness, and in pregnancy and breastfeeding. [1]
• Children and teenagers. The 1% drops are for adults only, and the 0.1% label's one children's use (from age 7) is a prescription treatment. Home-made sprays and injections have never been studied in anyone under 18. [1], [2]
• Home-made sprays and research-powder injections are unverified. Their strength, sterility and stability are unknown, no Semax spray pump has been tested, and there are no human safety data for injected Semax. [7]
• Read the units. mcg means micrograms; 1 mg equals 1,000 mcg. A drop of licensed 0.1% Semax holds 50 mcg and a drop of 1% holds 500 mcg; a home-made spray holds whatever its mix and pump deliver. "Per nostril" amounts are half of the dose. On an insulin syringe, a unit measures liquid, not Semax; check any amount with the reconstitution calculator.

Titration Changing the amount in steps

The label gives a range for each use rather than steps, and larger label doses are reached by repeating drops 10–15 minutes apart. [1] Websites usually start at about 200 mcg and move up: one injection page rises to 500 mcg in two-week steps over six weeks, another from 200–300 mcg to 300–500 mcg after 3–5 days. [20], [17]

Breaks and cycles

For adults, the label gives fixed courses of 3–14 days (10 for stroke), and the children's course is 30 days; courses are repeated "if necessary" with no stated gap. Websites add breaks of 2–3 days to 4 weeks, or 5 days on and 2 off. No study has compared break lengths. [1], [17], [13], [21]

Low, mid and high are alternatives, not steps to move through. The cited references give the full details.

Where protocols differ: drops, sprays, injections and breaks ↓

What is Semax commonly used for?

Most people outside Russia look into Semax for focus, mental energy and "brain fog", often alongside ADHD (attention deficit hyperactivity disorder), long work days or recovery from illness. In Russia it is prescribed mainly after stroke and for memory problems caused by poor blood flow to the brain. [27], [28], [1]

The two rest on different evidence. The Russian studies tested nose drops in patients, while the focus use rests on personal accounts and animal research. The sections below keep them apart.

Doserly

Where the human evidence on Semax is

Acute ischemic stroke

120 given Semax · 40 placeboDescribed as randomized, method not reported6, 12 or 18 mg/day for 5 days, 40 per dose

Long-term poor brain circulation

187 given Semax · 118 usual careComparison group, not randomizedrepeated 3-week courses

Optic nerve disease

54 given Semax · 20 usual careComparison group, not randomizeddrops or electrophoresis; controls also improved

Psoriasis with metabolic syndrome

60 given Semax · 58 standard careComparison group, not randomized600 mcg/day for 10 days; measured hormones

Glaucoma

24 given Semax · 12 salt-water dropsComparison group, allocation not described15-day course; both groups improved

Motor neuron disease

27 given Semax · No comparison groupNo comparison groupno effect on the disease

Healthy volunteers (brain scans)

14 given Semax · 10 placeboPlacebo comparison; single dose; scans onlybrain-network scans 5 and 20 minutes after one dose

Everyday focus or memory in healthy adults

No trial foundNo trial found

All studies gave Semax through the nose. Most come from the research network that developed Semax.

Selected studies with reported group sizes, one per condition. Numbers are people given Semax (teal) and in the comparison group (grey).

Most human studies are in patients, all given Semax through the nose; none tested everyday focus or memory in healthy adults.

Focus, mental energy and brain fog

This is the main reason people try it, and the least studied. No trial has measured everyday focus, memory or productivity in healthy adults. The older healthy-volunteer studies measured alertness, brain waves or brain scans after one or a few doses. [7], [29]

The Russian label does list "prevention of mental fatigue", monotonous operator work and adapting to heavy strain as uses, with a 3–5-day course. We found no published trial of that course. [1]

ADHD and attention

The 0.1% label includes children aged 7 and over with minimal brain dysfunction, including ADHD. The only comparison we found is a Russian review's summary of a 2000 study in 78 children aged 7–10: after 30 days, 50% improved on Semax, 48% on piracetam (another nootropic drug) and 10% on a multivitamin. The original report could not be retrieved, and the summary does not say how children were assigned or whether anyone was blinded. The FDA did not evaluate ADHD because it found no supporting literature. Adult ADHD is a common reason people try Semax online; it has not been tested for it. [1], [30], [7]

Stroke recovery

This is where most of the human research is. Russian studies gave Semax through the nose at 6–24 mg a day in the first days after an ischemic stroke (one caused by a blocked artery), and report faster recovery of movement and other lost functions than usual care alone. The studies are mostly small, not randomized and run by the developers' network. The human research section gives the details. [31], [32], [33]

Memory problems from poor brain circulation, and eye disease

The label's main 0.1% use is memory and thinking problems from long-term poor blood flow to the brain and after mini-strokes, where two larger Russian studies report better function than in untreated patients. Russian eye clinics also use the drops for optic nerve damage and glaucoma, where comparison groups often improved too. [1], [34], [35], [36]

Anxiety, mood and depression

Some people use Semax for low mood or anxiety. [37] Some community education groups also list it for anxiety. The Russian label is more cautious: it lists "neurotic disorders" and work under stress among its uses, but rules Semax out for disorders that come with anxiety. Rat studies found mixed antidepressant-like effects, and no human study has isolated Semax's effect on mood or anxiety; a report in teenagers with depression combined it with therapy. [1], [38], [39]

Other uses you may come across

Small Russian studies looked at stomach ulcers, migraine and motor neuron disease (see human research). Tinnitus, long COVID and head injury appear in personal accounts. Recovery after head injury is a labeled use in Russia, but we found no published human study of it; the other two have not been studied. [40], [41], [1], [42], [43], [44]

Where do Semax protocols differ?

Semax amounts look simple until you notice that people count in drops, sprays, micrograms per nostril and micrograms per day, for three different products. Here is what changes between them and why it matters.

Is the number for one drop, one spray, one dose or the whole day?

The same "3 drops" can differ tenfold. One drop of licensed 0.1% Semax holds 50 mcg and one drop of the 1% holds 500 mcg. Some pages get this wrong: one says a 0.1% drop is about 30 mcg, another says 1–2 drops of 1% are 100–200 mcg (they are 500–1,000 mcg). [1], [2], [25], [45]

Home-made sprays are harder still: 10 mg mixed in 5 mL gives 200 mcg per 0.1 mL pump, the same powder in 10 mL gives 100 mcg, and many pumps are not 0.1 mL. Per-nostril figures trip people up too: 600 mcg per nostril twice a day is 2,400 mcg a day, not the 1,200 mcg one page gives. [12], [46]

The 1% label allows 6,000–20,000 mcg a day in the first days after a stroke, and the Russian stroke studies tested 6–24 mg a day. A stroke result does not show that a 200–600 mcg "focus" dose works, and pages that call the stroke doses injections or drips are wrong: the label and the studies used nose drops. [2], [31], [32], [26]

Doserly

The same count, different amounts

Licensed 0.1% drops

1 drop =

50 mcg

3 drops =

150 mcg

Licensed 1% drops

1 drop =

500 mcg

3 drops =

1,500 mcg

Home-made spray (example)

one spray = 0.1 mL

10 mg in 5 mL:

200 mcg per spray

10 mg in 10 mL:

100 mcg per spray

depends on the mix and the pump

Drop amounts from the Russian label. Spray amounts are worked examples from a dosing website, not tested doses.

“3 drops” or “2 sprays” means nothing without the strength.

Nose drops, nasal spray or injection?

The human studies gave Semax through the nose. Subcutaneous injections are common online and people split on which route they prefer, but there are no human data on injected Semax: no safety study, no blood levels, no dose comparison. Pages that convert between routes are guessing; one gives 750–1,000 mcg by nose but 100–300 mcg by injection. [7], [47], [48]

Morning only, weekdays only or as needed?

Semax is usually taken early in the day because it can disturb sleep; the label's fatigue schedule already says "first half of the day". People also use it on workdays only (5 days on, 2 off), or only on demanding days. None of these patterns has been compared. [1], [17], [49], [50]

How long, and are breaks needed?

Adult label courses are short (3–14 days, 10 for stroke; the children's course is 30 days) and repeated "if necessary"; one long Russian study repeated a monthly course up to six times a year for three years. Websites instead describe cycles such as 10–14 days on and 2–3 off, or 2–4 weeks on and 1–2 off, usually "to prevent tolerance". No study has tested whether breaks do that, and one page's claim that its cycle "is built into Russian clinical protocols" is not supported. [1], [35], [17], [18]

How do micrograms convert to syringe units?

Semax for injection is sold as a powder in a vial that is mixed with sterile water. On a U-100 insulin syringe, units measure volume, not drug. For example, a 5 mg vial (5,000 mcg) mixed with 2.5 mL gives 2,000 mcg per mL, or 20 mcg per unit, so 300 mcg would be 15 units. The same 300 mcg is 30 units if the vial is mixed with 5 mL. Doserly's reconstitution calculator works this out for any vial and shows each step. [13]

What happens when you stop Semax?

No study has looked for withdrawal effects or a rebound, and the FDA notes that Semax's potential for misuse has never been assessed. Most human courses lasted 5–21 days, with outcomes measured during treatment or soon after. [7]

• How long effects last. In a Russian study of poor brain circulation, benefits were estimated to last 4–6 weeks after a 3-week course, and repeat courses did not build up. In diabetic eye disease, vision gains with nose drops were back to the starting level by six months. [34], [51]
• Side effects. In a study of stroke and long-term poor brain circulation, about 7% had a cold, pale nasal lining, which settled after a 1–2-day pause and oily nose drops. [35] In one public account, dizziness went away after stopping. [52] In community education groups, people describe irritability, anxiety and poor sleep settling within days of stopping; these are personal reports, not measured recovery times.
• Focus effects. Some people describe focus dropping on days off or after stopping, others describe benefits lasting days or months, and one found a faded effect did not return after a two-month break. [53], [27], [54]

The label says nothing about stopping or tapering, website claims of "no dependence" have no test behind them, and the breaks websites recommend are a user convention. [1], [17]

Do nasal drops, sprays and injections behave the same way?

Nobody knows, because Semax has never been measured in human blood by any route. There is no human pharmacokinetics study, so there is no measured bioavailability, peak level or half-life for drops, sprays or injections. [7]

The label says up to 60–70% of a nasal dose is absorbed and that Semax passes quickly into the brain, but no human study measuring either has been published. In rats, about 0.09% of a nasal dose per gram of brain tissue was found in the brain two minutes later, mostly intact; after an injection into a vein, only about 0.005% of the dose reached the brain at its peak. [1], [57], [58], [7]

Doserly

What has been measured for each form of Semax

Licensed nose drops

Tested in people

●Yes: Russian patient studies (drops, or electrophoresis through the nose)

Blood levels in people

○Not measured

Reaches the brain

◐Rat studies: small share within minutes

Amount per dose

●50 mcg (0.1%) or 500 mcg (1%) per drop

Storage tested

●Label: 2–8 °C; up to 30 days at ≤25 °C after opening

Home-made nasal spray

Tested in people

○No

Blood levels in people

○Not measured

Reaches the brain

○Not measured

Amount per dose

○Depends on the mix and the pump

Storage tested

○No stability data

Injection under the skin

Tested in people

○No human data

Blood levels in people

○Not measured

Reaches the brain

○Not measured

Amount per dose

○Depends on the mix

Storage tested

○No stability data

N-acetyl Semax amidate / Adamax

Tested in people

○No (different molecules)

Blood levels in people

○Not measured

Reaches the brain

○Not measured

Amount per dose

○Unknown

Storage tested

○No stability data

● measured, tested or on the label◐ animal data only○ not measured or no data

Sources: FDA briefing 2026 (no human pharmacokinetic or injection studies), rat nasal transport study 2006, Russian 2025 label.

Only nasal Semax (drops or electrophoresis through the nose) has been studied in people, and no form has had its blood levels measured in people.

Is a home-made spray the same as the licensed drops?

Not necessarily. The licensed drops are a fixed 0.1% or 1% solution with a preservative (methylparaben) and a stated amount per drop. A home-made spray from a research powder has an unverified amount of peptide, an unknown pump volume and no stability data, and the FDA noted that no Semax spray pump has been tested. [1], [2], [7]

How long does Semax last in the body?

In people, its half-life is unknown. Enzymes break it down fast: in rat blood only about 0.7% was intact after an hour in a laboratory test, and its main breakdown product is the tripeptide Pro-Gly-Pro (PGP). [59], [57], [7]

An older label version and a developer review say one dose acts for 20–24 hours, crediting its breakdown pieces. That is a claimed effect duration, not a blood measurement. Website half-lives, from a few minutes to about half an hour, have no human measurement behind them either. [24], [60], [61], [21]

Is N-acetyl Semax amidate (NASA) or Adamax a stronger Semax?

They are different molecules: N-acetyl Semax amidate ("NASA") has chemical caps on both ends and Adamax has an extra adamantane group, and neither has published human data. Some pages list NASA as another name for Semax or give it smaller doses on the untested assumption that it is stronger. [62], [63], [45]

Is Semax acetate different from Semax?

It is the same peptide as an acetate salt, a common form for peptide powders. The FDA treats the two as separate ingredients, but no study has compared them in people. [7]

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

For the licensed drops, the answer comes from the label. For research powders and home-made sprays, no shelf life for human use has been established.

• Licensed drops (current 2025 label). Keep at 2–8 °C, away from light, and do not freeze; unopened shelf life is 2 years. Once opened, keep at up to 25 °C for no more than 30 days. Older labels gave no limit after opening, and a manufacturer question-and-answer page says six months; the current label's 30 days is the figure to follow. [9], [10], [22], [64]
• Research powder. Laboratory suppliers give their own conditions, such as −20 °C for the dry powder; one advises against keeping it dissolved for more than a day, another says 2–7 days at 4 °C. These are statements for laboratory material, not drug labels. [65], [66]
• Mixed vials and home-made sprays. Dosing websites give about 2–4 weeks in the fridge without citing a Semax stability test; one says its estimate is borrowed from similar peptides. No study has measured how long a home mix keeps its strength. [13], [18]

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

What do we actually know about Semax in people?

More than for most research peptides, but less than its Russian approval suggests. The human studies are almost all Russian, mostly from the network that developed Semax, and most compared Semax with usual care without random assignment. All gave it through the nose, and none is registered on ClinicalTrials.gov. [7], [56]

What did the stroke studies find?

The FDA judged the stroke evidence "insufficient" but did not review the Russian-language studies because they were not translated. That is a limit of its review, not a finding that those studies were negative; they have design weaknesses of their own. [7]

What about memory problems from poor brain circulation?

• 2005. 187 patients given 3-week courses, compared with 118 who were not: fewer worsenings, with benefits estimated to last 4–6 weeks after each course. [34]
• 2012. 120 patients took 0.1% drops three times a day for a month, up to six times a year for three years, compared with 32 who did not; the most affected group gained 2.5 times as much function as controls at one year and 3 times as much at three. [35]

Neither study was randomized, so healthier or more motivated patients may have ended up in the Semax groups.

Eye, ulcer, pain and other studies

• Optic nerve disease, 2000. 74 patients: 25 given drops, 29 given Semax by electrophoresis through the nose, and 20 on usual care. Vision improved in all three groups, including the comparison group. [36]
• Glaucoma. A 2012 study of 110 patients does not give clear group sizes. In a 2014 study, 24 people on Semax and 12 on salt-water drops both improved, with a larger gain on Semax in one measure of visual sensitivity; the paper does not say how people were assigned. [68], [69]
• Peptic ulcer, 2002. Added to standard ulcer drugs for 10 days, 89.5% of ulcers healed by day 14 versus 30.8%; assignment not described. [40]
• Migraine and nerve pain, 1996. One nasal dose stopped migraine pain in 4 of 12 people; the authors concluded Semax had no pain-relieving effect of its own. [7]
• Motor neuron disease, 2007. An open study of 27 patients found no effect on the disease. [41]

Has Semax been tested in healthy people?

Only briefly: a 1996 study of 19 men measured alertness and brain waves after 1 mg by nose a day for two days or a single 0.25 mg dose, a scan study compared 14 people given one dose with 10 given placebo, and a second scanned 52 volunteers across Semax, Selank and placebo (its Semax group may be the same people). A larger resting brain network is not the same as better thinking. No study has tested focus, memory or work performance over weeks of use. [7], [29], [70]

How might Semax work?

Nobody knows how Semax works in people. The explanations below come from rat and mouse studies and from cells in a dish, almost all from the developers' network. Rodent doses (typically 50–250 mcg per kilogram by nose) cannot be converted into human doses. [7], [71]

Does Semax raise BDNF?

In rats, yes. One nasal dose of 50 mcg per kilogram raised BDNF (brain-derived neurotrophic factor, a protein that helps nerve cells survive and form connections) in the hippocampus, a memory area, by up to 1.4 times, and increased the activity of its receptor, TrkB. Other rat studies found genes for BDNF and nerve growth factor switched on within an hour. [71], [72], [73]

In people, the only measurement is higher blood BDNF in stroke rehabilitation patients. Nobody has measured brain BDNF in people, and online claims of "BDNF up 300–800%" have no source. [67]

Does it protect the brain after a stroke?

In rat stroke models, Semax reduced the damaged area and changed the activity of hundreds of genes linked to inflammation and nerve signalling. That fits the Russian stroke studies but cannot confirm them. [74], [75]

Does it act like a stimulant?

Partly, in animals. In rodents, Semax did not change dopamine by itself but raised a serotonin breakdown product and made amphetamine's effect on dopamine and movement stronger: mice given both moved about 261% of their baseline, compared with 182% on amphetamine alone. The FDA flags this as a reason Semax's misuse potential should be studied. [76], [77], [7]

Is Semax a hormone? Does it raise cortisol?

It is built from a small part of ACTH, and 1986 animal tests found it did not trigger steroid release. The label calls it "completely devoid of hormonal activity". [8], [1]

The only human study that measured it points the other way. In 60 people with psoriasis and metabolic syndrome given 600 mcg a day for 10 days with standard care, blood cortisol rose by 28.2%, from below the level seen in healthy volunteers toward it, and ACTH fell by 28.9%, compared with 58 on standard care alone. It was not randomized, so it does not prove Semax raised cortisol, but claims that it "lowers cortisol" or works "without triggering stress hormones" are not supported. [78]

Does it affect pain or blood clotting?

In rats, pain results depended on the test, and an enzyme effect in human blood samples needed high laboratory concentrations. Rats given Semax also had more clot-dissolving activity and less platelet clumping, which the FDA says could mean a bleeding risk with blood thinners; this has not been studied in people. [79], [80], [7]

What are the risks and unanswered questions?

Is Semax safe?

Nobody has shown that it is safe outside its licensed use. Its safety record comes only from Semax given through the nose, mostly in short courses, and it is thin: the label lists one side effect, mild nasal irritation, and most studies did not say how they checked for side effects. The FDA found no standard toxicity, genetic-damage, pregnancy or cancer studies, and there are no safety data for injected Semax. [1], [7]

What side effects have been reported?

People using research sprays and injections also describe poor sleep, irritability, anxiety, headaches and a feeling of emotional flatness; those accounts are covered in what people report.

Can Semax cause seizures?

It might in people prone to them, and the label rules it out for anyone with a seizure history. In patients recovering from oxygen starvation of the brain, seizure-like activity appeared only after a large single dose, and the authors advised a brain-wave check when treatment starts; in animals, results were mixed. [1], [81], [82], [83] Some community education groups list Semax for "seizure recovery", which contradicts the label.

Does Semax cause hair loss?

No study has looked. Some people online describe shedding or bald patches, one with regrowth after stopping, while others say their hair was unaffected; none of these accounts can show cause, and the proposed link through cortisol is unproven. [84], [53], [54]

Is Semax addictive?

This has not been studied. The FDA says Semax's potential for misuse has not been assessed, and points to rodent studies in which Semax strengthened amphetamine's effect on dopamine and movement. No published report describes withdrawal or dependence, but no study was designed to find it. [7], [77]

Could product quality change the risk?

Yes. The licensed drops are made under Russian drug rules; research powders and sprays are not. The FDA noted no data on impurities, clumping (aggregation) or bacterial toxins for compounded Semax, and that injected or sprayed peptides may trigger immune reactions. Belgian laboratories confirmed Semax in a seized vial but did not test its purity. [7], [85]

Is Semax legal? Is it FDA-approved?

Checked September 23, 2026. Rules differ by country and change quickly. A "research use only" label does not make a product legal to sell or safe to use.

United States. Semax is not an FDA-approved medicine. The key steps:

• Nominations withdrawn. Two companies asked the FDA to let pharmacies compound Semax, then withdrew. The FDA's list of compounding ingredients with safety concerns shows it as "nominated but withdrawn", warning of possible immune reactions and limited safety information. [7], [86]
• 2026 staff review. The FDA reviewed Semax for brain ischemia, migraine and trigeminal neuralgia, found the evidence insufficient and recommended against compounding. [7]
• July 24, 2026. Its Pharmacy Compounding Advisory Committee voted 8 to 5, with 1 abstaining, to recommend adding Semax, as both the free base and the acetate salt, to the list of bulk ingredients pharmacies may compound. An advisory vote is not an FDA decision. [87], [88]
• Now. No final decision had been published by September 23, 2026, and Semax is not on the list of bulk ingredients US pharmacies may use. [89], [90], [91]

Canada. Health Canada named Semax in an August 2025 advisory about seized unauthorized injectable peptides, and we found no Canadian authorization. [92]

Australia. Semax is not named in the June 2026 Poisons Standard, and we found no Australian approval or regulator statement naming it. A missing name does not make it legal to sell or import. [93]

United Kingdom and Europe. We found no UK or European Union authorization for Semax and no regulator statement naming it, as of September 2026.

Russia and Ukraine. In Russia, the 0.1% and 1% drops are prescription medicines, registered again in 2025 and on the official list of essential medicines. A Ukrainian registration expired in 2014, so pages calling it approved there are out of date. [1], [2], [94], [95]

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

It is not named on the World Anti-Doping Agency's 2026 or 2027 lists. Their S0 rule bans substances with no current approval by any government health authority; because Semax is approved in Russia, it is unclear whether S0 covers it, and we found no athlete case. Competitive athletes should check with their anti-doping organization. We found no published test for Semax in urine or blood, although laboratories can identify it in products. [96], [97], [85]

Who should be especially cautious?

The label rules out the first four groups. The others are cautions from studies or have not been studied, which is a reason for caution, not proof of harm.

• Anxiety disorders. Ruled out by the label, and anxiety and irritability are common complaints online. [1]
• A history of seizures, psychosis or acute psychiatric illness. [1], [81]
• Pregnancy and breastfeeding. No studies were done. [1]
• Children and teenagers. The 1% drops are for adults only. The 0.1% label allows one children's use from age 7 but rules out under-18s for eye and brain-surgery uses, and the children's ADHD listing rests on a small comparison known only from a secondhand summary. [1], [2], [30]
• Diabetes, because of the blood-sugar rise; the stroke guide advises caution in poorly controlled diabetes. [31]
• Blood thinners, because of the rat clotting findings. [7]
• Stimulants, antidepressants or mood stabilisers. Interactions are unstudied, and Semax strengthened amphetamine's effects in rodents. [77] In community education groups, some people describe cutting or stopping these medicines when starting Semax, often without their prescriber; changes to a prescribed medicine belong with the prescriber.
• Paraben allergy, for the 1% drops' preservative warning. [10]
• Drug-tested athletes, because of the S0 rule. [97]

Has Semax been tested alongside other medicines?

Not in a formal interaction study. Several Russian studies gave Semax alongside standard treatments, but none tested interactions with specific medicines. The label's only interaction advice is to avoid decongestant nose drops (the kind that narrow blood vessels) at the same time, the FDA's stimulant and blood-thinner concerns come from animal studies, and nothing is known about Semax with antidepressants, ADHD medicines, alcohol or Selank. Bring a complete list of everything you take to a pharmacist or doctor. [1], [7], [77]

What should be monitored while using Semax?

The Russian label sets no blood tests or check-ups. What exists is a record of what the studies measured and what they found, which can help you prepare questions for a clinician; it is not a personal testing plan.

What does the label ask for?

No routine blood tests or check-ups. The labels list the conditions in which Semax should not be used and advise against decongestant nose drops at the same time; the 1% label also warns that its preservative can cause allergic reactions and, rarely, airway tightening. Neither label has driving-study data. The 1% drops are meant for acute stroke as part of combined treatment. [9], [10]

What did the human studies check?

• The 2011 stroke guide measured blood pressure, pulse, heart tracings (ECG), blood chemistry, blood sugar and brain waves (EEG) for 30 days; blood pressure and ECG did not change meaningfully. [31]
• The 2005 circulation study checked brain waves, ECG, blood counts, blood sugar and cholesterol; blood sugar and brain waves did not change. [34]
• The posthypoxic studies recorded brain waves in patients recovering from oxygen starvation of the brain; three had seizure-like activity after a 3 mg nasal dose, and the authors advised an EEG at the first dose. The psoriasis study found cortisol higher and ACTH lower. [81], [82], [78]

Which signals matter, and why?

A seizure or a severe allergic reaction needs urgent medical care rather than tracking. [81], [10]

These come from small studies and personal accounts, so they show what has been flagged, not what a person will experience.

What do people in public communities report?

Public forums, Russian review sites and community education groups contain enthusiastic reports, flat disappointments and a steady stream of sleep and mood complaints, often in the same thread. Most people online use research sprays or injections, not the licensed drops, and most take other things too. These are selected discussions, not a survey of everyone who has tried Semax.

What do the positive reports look like?

The typical success story is a short lift in focus and drive, with less brain fog and easier word-finding. One person on 400 mcg twice a day for two weeks described sharper recall but also emotional blunting and worse sleep; another, after years of on-and-off use, took 250 mcg with Selank every morning for one to two months and credited it with better ADHD symptom control. [98], [27]

Accounts from people using the licensed drops are more mixed: one described longer focus but feeling spacey and less social; a caregiver saw no memory benefit in an elderly parent after two years of two-week courses. [99], [101]

How fast does it work, and how long does it last?

Nasal users describe an effect within minutes that fades after a few hours; injection users describe a slower, milder, longer effect, a pattern that recurs in community education groups. People split on which route they prefer, and several found one route did nothing while the other worked. [102], [103], [104]

Does everyone notice something?

No, and "nothing happened" is one of the most common stories: one person noticed nothing at 500 mcg a day, another after five days of injecting 500 mcg each of Semax and Selank, and another after up to 10 drops at a time. The explanations offered (wrong route, too little per spray, a poor batch, a healthy brain having little to gain) are untested. [50], [103], [105], [106] In community education groups, nonresponders appear on both routes and at every dose.

What unwanted effects come up?

The recurring complaints are poor sleep when dosed late, irritability, anxiety, headaches and an afternoon slump. Less common reports include emotional blunting, worse word-finding after a couple of weeks, dizziness, hair shedding and a fainting episode in an overheated classroom. Russian reviewers of the licensed drops described severe headaches, confusion and trouble reading after the first doses. [98], [100], [52], [84], [107], [108] In community education groups, these complaints cluster at higher or quickly raised doses and settle within days of stopping.

Does it stop working over time?

Some say it does. One described a strong early effect that faded over months and did not return after a two-month break; another suspected rising tolerance after two months of weekday use. Others describe steady effects across cycles. [54], [49], [48] In one community education group account, a faded effect returned after a two-week break. No study has tested tolerance.

How can you judge a Semax story?

Ask: Was it the licensed drops, a home-made spray, an injection, or N-acetyl Semax amidate sold under the same name? How many micrograms, rather than "sprays" or "units"? What else changed: Selank, caffeine, ADHD medicine, antidepressants, sleep, work? Was anything measured, or only felt? Did the person post again weeks later? Focus is where expectation matters most, and one good day proves little.

How does Semax compare with Selank, Dihexa and Pinealon?

These peptides are sold side by side as "brain" peptides and often stacked. Of the four, only Semax and Selank are registered medicines, both in Russia.

Semax and Selank are Russian medicines with small Russian studies behind them; Dihexa and Pinealon have no approved use and little or no human research. The only direct comparison is a brain-scan study of 52 healthy people given Semax, Selank or placebo, which did not test symptoms or safety, so the table cannot say which works better or is safer. [70]

Semax and Selank are made by the same Russian company and are often combined, Semax in the morning for focus and Selank in the evening for calm, or mixed in one spray. That combination has never been studied, and in a mixed spray the amount of each per press depends on how it was made. [111], [27]

Common questions about Semax

How long does Semax take to work?

People who notice an effect usually describe it within half an hour of a nasal dose, more slowly after an injection; many notice nothing. The stroke studies measured recovery over days to weeks. [102], [50], [35] See what people report.

Is Semax a stimulant? Is it like Adderall?

Not in the usual sense: it did not raise dopamine by itself in animal studies, though it strengthened amphetamine's effect. Many people describe it as activating, with better focus and sometimes poor sleep or irritability. It has never been compared with ADHD medicines. [76], [77], [98] See how it might work.

Can Semax replace ADHD medication or an antidepressant?

There is no evidence that it can. The label's ADHD listing for children rests on a small 2000 comparison known only from a review's summary, in which Semax did about as well as piracetam, and Semax has never been tested in adults with ADHD or depression. Any change to a prescribed medicine belongs with the prescriber. [30], [7] See who should be cautious.

Is Semax the same as Selank? What is the Semax and Selank stack?

No. Selank is a different seven-amino-acid peptide, sold in Russia as non-prescription anxiety drops, that shares only Semax's last three amino acids. The "stack" usually means Semax in the morning and Selank in the evening, or both in one spray; the combination has not been studied. [80], [111], [27] See how they compare and the Selank guide.

Does Semax raise or lower cortisol?

The only human measurement found cortisol 28% higher after 10 days, rising from below-normal levels, in a non-randomized study of people with psoriasis on other treatment. That does not prove Semax raises cortisol, but claims that it lowers it are not supported. [78] See the hormone question.

Is Semax approved in Russia? Is it legal to buy?

It is a prescription medicine in Russia, as nose drops. It is not FDA-approved or on the federal list of bulk ingredients US pharmacies may use for compounding, and we found no approval in Canada, Australia, the United Kingdom or the European Union. The Russian approval covers the licensed drops, not research sprays or injections, and a "research use only" label does not make a product legal to sell. [1], [7], [89] See the dated legal-status summary.

Can you take Semax every day, long term?

Long-term daily use has not been studied. Adult label courses last 3–14 days (the children's course is 30 days) and are repeated when needed; the longest study repeated monthly courses up to six times a year for three years. Weekday-only and cycled schedules online are conventions, not tested plans. [1], [35], [17] See where protocols differ.

Glossary

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

ACTH

Adrenocorticotropic hormone, a pituitary hormone that tells the adrenal glands to release cortisol. Semax is built from a small piece of it that lacks this hormone effect in animal tests.

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. Clumps can make a product weaker and, when injected, 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 or mice. It shows what a substance does in a living body, but results in people can differ.

BDNF

Brain-derived neurotrophic factor, a protein that helps nerve cells survive, grow and form connections. It works through a receptor called TrkB.

Bioavailability

How much of a dose reaches the bloodstream in a usable form. It depends heavily on the route.

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.

Compounding

When a pharmacy prepares a customized medicine from individual ingredients. In the US, federal lists control which bulk ingredients pharmacies 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 10 days. A cycle is a course plus a planned break before any further use.

Daily total

All the amounts given in one day, added together. For example, 250 mcg twice daily is a 500 mcg daily total.

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 taken with pads on the skin.

EEG

Electroencephalogram, a recording of the brain's electrical activity (brain waves) taken with sensors on the scalp.

Half-life

The time it takes for the measured level of a substance in the blood to fall by half. It is not the same as how long an effect lasts.

Intranasal

Given into the nose, as drops or a spray, to be absorbed through its lining. The licensed Semax drops are intranasal.

Investigational

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

Freeze-dried (lyophilized)

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

mcg and mg

Micrograms and milligrams. 1 mg equals 1,000 mcg. One drop of 0.1% Semax holds 50 mcg; one drop of 1% Semax holds 500 mcg.

Nootropic

A substance taken in the hope of improving thinking, focus or memory. The word describes how a product is used or marketed, not proof that it works.

Peptide

A short chain of amino acids. Semax is a chain of seven.

Pharmacokinetics

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

Placebo

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

Preclinical research

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

Reconstitution

Mixing a freeze-dried powder with a liquid so it can be measured. The amount of peptide in the vial and the volume of liquid added together set how much each unit or spray holds.

Registered medicine

A medicine a country's regulator has approved for sale for specific uses, with an official label. Semax is registered in Russia, not in the United States or the European Union.

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.

Subcutaneous (SC)

Injected into the fatty layer just under the skin. Many online Semax users inject this way, although no human study has tested it.

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 Semax in people.

Explore more of the research

Go deeper into the animal and laboratory experiments behind the mechanism claims.

Across this guide, the citations include 43 original scientific papers: 19 human studies and 24 cell, animal and laboratory studies. The optional library below summarizes selected animal and cell papers by question. Paper counts are not counts of independent research teams: most Semax papers come from one Moscow research network.

In the route details, intraperitoneal means into the abdominal cavity and intravenous means into a vein.

How this guide was researched

This guide is built from a thorough review of the sources cited throughout it: published scientific studies, official Russian product labels, regulatory documents and published protocol descriptions. We also reviewed public online forums, Russian review sites and community education groups where people describe their own experiences with Semax.

The guide cites 122 sources, including 43 original scientific papers. Each type of source answers a different question. Studies show what researchers measured. Labels show how the licensed product is meant to be used. Protocol descriptions show how Semax is typically used online. 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