Semax
ACTH (4-10) analogue · Met-Glu-His-Phe-Pro-Gly-Pro
Semax is a synthetic analogue of a fragment of ACTH, developed in Russia in the 1980s. It occupies an unusual regulatory position: it is an approved medicine in Russia, listed on their essential medicines list, and used clinically there for stroke and cognitive indications. It has no approval anywhere else.
That matters for how the evidence reads. A substantial clinical literature exists, and most of it is Russian-language, conducted domestically, and has not been replicated by independent groups elsewhere. That is not a reason to dismiss it, and it is not the same as the multi-centre international evidence behind an FDA-approved drug. Both statements are true and readers usually get only one.
It is also unusual here in route: semax is used as a nasal solution, not injected. Anything on this page about drawing and reconstituting concerns preparing drops, not a syringe.
How it works
Semax has been reported to increase expression of brain-derived neurotrophic factor and nerve growth factor in the brain, signalling proteins involved in neuron survival and plasticity. That is the most-cited proposed mechanism for the cognitive claims.
It also appears to influence the melanocortin system, unsurprisingly given it derives from an ACTH fragment, though the fragment was chosen specifically to avoid the parent hormone's effects on cortisol.
Nasal administration is used because it is small enough to reach the brain by that route with less first-pass loss than swallowing it would involve.
Regulatory status — United States
Approved and clinically used in Russia, where it appears on the essential medicines list. Not approved in the United States, the EU or the UK, and material sold in those markets is an unapproved substance with no manufacturing standard behind it.
Last reviewed 12 Aug 2026. Regulatory positions in this category change frequently; we date this line so you can see how current it is.
What it is studied for
Each entry states the evidence behind it. We do not rank indications by effectiveness — for most compounds here, that would be a claim nobody can support.
Stroke recovery
Published reviewIts approved indication in Russia.
EvidenceRussian clinical studies. Not replicated by independent groups outside Russia, and not reviewed by any other regulator.
Cognition and focus
Published reviewThe reason it is used outside Russia.
EvidenceRussian clinical and preclinical work. No independent controlled trial in healthy adults.
Identity and clearance
Molecule
- Class
- ACTH (4-10) analogue, heptapeptide
- Molecular weight
- 813.9 Da
- Length
- 7 amino acids
Sequence
Met-Glu-His-Phe-Pro-Gly-Pro
The Pro-Gly-Pro tail is a stabilising addition that considerably extends its life compared with the natural fragment.
Pharmacokinetics
Published reviewShort-acting. Which is why dosing is described several times a day. Effects on neurotrophic factor expression are reported to outlast the peptide itself.
Dose protocols reported in sources
Displayed for reference only. Every row says where it came from, and a trial protocol and a community convention are not the same kind of information. None of this is fed into the calculator, and none of it is a recommendation.
| Goal | Dose | Frequency | Route | Units, 5 mg vial | Source | Start this protocol |
|---|---|---|---|---|---|---|
| Commonly described nasal dose | 300 mcg – 600 mcg | Once or twice daily, split between nostrils | NasalUsed as drops. Higher ranges are described for the stroke indication in Russian clinical use, under supervision. | 12–24 u | Community practice | Start this |
Start this copies a row into a protocol of your own, which you can then edit. Where a source gave a dose range or an ambiguous frequency, those fields arrive empty — we will not pick a number on your behalf.
CheckRows marked community practice describe what people commonly do, drawn from public discussion. They are not derived from any trial and are not evidence that a dose is safe or effective.
Safety
Reported effects
- Nasal irritation or drynessCommunity practice
Commonly reported
The most frequent complaint, and a direct consequence of the route.
- HeadacheCommunity practice
Occasionally reported
- Overstimulation, irritability or disturbed sleepCommunity practice
Occasionally reported
More often described with evening dosing or higher amounts.
- Long-term effects outside clinical supervisionCommunity practice
Unknown
Its clinical use in Russia is short-course and supervised. Extended self-directed use is not what the evidence covers.
When to stop
- Persistent nasal pain, bleeding or crusting.
- Any allergic response: rash, facial swelling or difficulty breathing. Seek urgent care.
- Marked anxiety, agitation or insomnia that appears after starting.
- Any new neurological symptom — headache pattern change, visual disturbance, weakness.
Interactions and situations that need care
- Pregnancy and breastfeedingAvoid
No reproductive or developmental safety data outside Russian clinical use.
- Anxiety disordersUse caution
Overstimulation and irritability are among the more commonly reported effects, which is a poor fit alongside an anxiety disorder.
- Stimulant medicationUse caution
Semax is frequently described as stimulating. Combining it with prescribed stimulants adds an unquantified variable to a medication someone is already titrating.
What to expect
- Human clinical evidence exists, and it is essentially all Russian, domestic, and unreplicated by independent groups elsewhere. Weigh it accordingly rather than dismissing or over-reading it.
- Its approved use is a short supervised course, for stroke and specific cognitive indications. Not indefinite self-directed use in healthy adults.
- Effects reported by users are typically described as subtle and same-day rather than accumulating.
- Nasal irritation is the most consistently reported downside and follows from the route.
Storage and handling
- Freeze-dried powder
- Refrigerated at 2–8 °C, protected from light.
- After mixing
- Refrigerated at 2–8 °C. Nasal solutions are entered repeatedly, so bacteriostatic water rather than sterile water matters here.
- Long-term, frozen
- Unopened powder is stable at −20 °C or colder.
With other peptides
- N-Acetyl Semax Amidatecaution
The amidated form is a modified Semax. Running both is taking the same compound twice, once in a form with Russian clinical use behind it and once in a form with none.
- Adamaxcaution
Sold as a Semax derivative, so running both risks taking the same thing twice. With no established structure for Adamax, even that cannot be said with confidence.
- Selanksynergistic
Commonly used together — Semax described as stimulating, Selank as calming. Both come from the same research programme, and no study has tested the combination.
Checking your vial
Research chemicals carry no manufacturing standard, so what the vial looks like is often the only quality signal available before you use it. More on assessing quality and COAs.
White cake, clear solution
Standard for a short peptide.
Cloudy solution
Particularly relevant for a nasal preparation entered repeatedly over weeks.
Questions
- Is Semax approved anywhere?
- Yes, in Russia, where it is used clinically and appears on the essential medicines list. It holds no approval in the United States, the EU or the UK.
- Why is the research all Russian?
- It was developed in Russia in the 1980s and its clinical development happened there. Most of the literature is Russian-language and has never been replicated by an independent group. That is a real limitation, and a different one from having no evidence at all.
- Is it injected?
- No. Semax is used as a nasal solution. It is reconstituted into a dropper or spray rather than drawn into a syringe.
References
Semax, an analogue of ACTH(4-7): neuroprotective and nootropic activity
Review literature, 2018 · Review
Humans and animal models
Reviews reported increases in BDNF and NGF expression, and summarises Russian clinical use in stroke and cognitive indications.
Commonly reported community protocols
Bioalmanac editorial summary of public community sources, 2026 · Not a study
Summarises nasal dose ranges described in public discussion outside Russia. Carries no evidential weight about safety or effect.
Related compounds
N-Acetyl Semax Amidate
Semax with both ends chemically capped so it lasts longer. More potent per milligram in animal work, and no human trial of the modified version exists.
Adamax
A Semax derivative sold with adamantane-related branding. The least documented compound on this site, and that is saying something.
Selank
A seven-amino-acid peptide developed in Russia and used there for anxiety. Nasal rather than injected, and the sibling compound to Semax.
GHK-Cu
A naturally occurring copper-binding tripeptide with a long history in topical skincare research. Injected use is not what the research studied.
Next
What to do with Semax
- Keep a record of itTurn a dose and a schedule into a protocol, then log what you actually take. Semax is filled in for you.
- See what it costsPer-milligram prices read from vendor sites and confirmed by a person, so vial sizes compare.
- Check a combinationWhat our profiles record about Semax alongside each other compound — including the pairs where nothing is recorded.
Keep this page honest
If something here is wrong, out of date, or missing a source, tell us and we will fix it and say that we did.
This page is educational. It describes what published research reports, not what you should do. Peptides discussed here are largely not approved for human use, and nothing on Bioalmanac is medical advice. No clinician reviews these pages.
Page last updated 12 Aug 2026