Semax (Methionine-Glutamyl-Histidyl-Phenylalanyl-Prolyl-Glycyl-Proline)
Russian-developed heptapeptide, ACTH(4-10) analog
At a glance
What it is: Russian-developed heptapeptide, ACTH(4-10) analog.
Primary research applications:
- Approved in Russia: stroke recovery, ADHD, memory disorders
- Off-label: cognitive enhancement
Editorial summary: Semax is approved in Russia for neurologic and cognitive indications with reasonable clinical use, but almost all published research is Russian and Western-reproduced studies are limited. Cognitive-enhancement claims in healthy adults are poorly substantiated.
What is Semax?
Semax is a synthetic heptapeptide analog of the 4–10 region of ACTH, with modifications intended to retain neurotropic effects while removing ACTH's hormonal activity. Developed in Russia in the 1980s and approved there for several neurologic indications.[1]
Mechanism of action
Effects attributed to Semax include:
- Upregulation of BDNF and nerve growth factor expression
- Modulation of neurotransmitter systems (dopaminergic, serotonergic)
- Neuroprotection in experimental ischemia models
What the research shows
The peer-reviewed literature on Semax is summarized below across two tiers: human research (the highest standard), and preclinical / emerging research (animal models and early-stage human work).
Claims and the evidence behind them
This table summarizes commonly discussed claims and how the published evidence weighs in. The aim is clarity, supported claims, claims that look promising but need more data, and claims that outrun the science.
| Claim | What the evidence shows | Verdict |
|---|---|---|
| Improves outcomes after ischemic stroke | Russian trials; approved indication in Russia | Supported |
| Enhances cognition in healthy adults | Limited controlled evidence; mostly user reports | Preliminary |
| Works as a nasal spray | Intranasal formulation is the approved form | Supported |
Reported user experiences
How the research describes administration
Russian-approved formulation is an intranasal spray. Some users also administer subcutaneously in grey-market settings, though this is not an approved route.
Editorial note
Administration details above describe how the peptide is given in published studies. We summarize this for educational completeness; these descriptions are not protocols, dosing recommendations, or instructions for personal use. Decisions about treatment require an appropriately licensed clinician.
Safety considerations and open questions
The takeaway
⚠ Regulatory update (July 2026): On July 23-24, 2026 the FDA Pharmacy Compounding Advisory Committee (PCAC) voted to recommend Semax for the 503A Bulks List, 8-5 with one abstention, against the advice of FDA's own staff reviewers. The vote is advisory: FDA must still complete notice-and-comment rulemaking before compounding eligibility actually changes, realistically into 2027 or later. See our FDA PCAC July 2026 review for the full context.
Semax is one of the more legitimately-used Russian peptides, it has real approved clinical indications there. Claims about cognitive enhancement in healthy people are less well-supported. User reports are often positive, but placebo effects for subjective cognition are notoriously strong.
Frequently asked questions
Is Semax legal in the US?
Not approved by the FDA. Imported as a research chemical or via grey-market sources.
Does Semax actually boost memory?
Russian clinical trials show improvements in post-stroke neurologic recovery. Memory improvement in healthy adults is less well-supported by controlled trials.
Is Semax safe?
Short-term use appears generally well-tolerated from Russian clinical experience. Long-term safety in healthy users is not characterized.
Regulatory status (July 2026)
Semax was one of seven peptides reviewed by the FDA Pharmacy Compounding Advisory Committee (PCAC) on July 23-24, 2026 for possible addition to the 503A Bulks List, evaluated for cerebral ischemia, migraine, and trigeminal neuralgia. On July 24 the committee voted to recommend it, 8-5 with one abstention — overriding FDA's own staff reviewers, who had advised against all seven on grounds of insufficient characterization and limited human data.
This does not change what may legally be compounded today. A PCAC vote is advisory: FDA must still act through notice-and-comment rulemaking before any substance joins the 503A list, a process realistically running into 2027 or later, and the agency can decline to follow the recommendation. Semax remains not an FDA-approved drug. For the full picture across all seven compounds, see our July 2026 FDA PCAC review.
References
- Asmarin IP. Nootropic analog of ACTH (4-10) -- heptapeptide semax (development, study, application). Zh Vyssh Nerv Deiat Im I P Pavlova. 1997;47(2):420-30. https://pubmed.ncbi.nlm.nih.gov/9206758/
- Gusev EI, et al. Semax in prevention of disease progression and development of exacerbations in patients with cerebrovascular insufficiency. Zh Nevrol Psikhiatr Im S S Korsakova. 2005;105(2):35-40. https://pubmed.ncbi.nlm.nih.gov/15796024/