Overview
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In plain language
Semax is a lab-made peptide of 7 amino acids developed in Russia. It is based on a small piece of ACTH, a stress hormone, but it does not act like a stress hormone.
In Russia it is approved as nasal drops for stroke recovery and some brain conditions. Most of its research comes from Russian groups and has not been confirmed in large international trials. It is not FDA-approved in the United States.
For students
Semax (MEHFPGP, about 814 Da) joins ACTH(4–7) (Met-Glu-His-Phe) to a stabilizing Pro-Gly-Pro tail. It was developed at the Institute of Molecular Genetics in Moscow, the same institute that developed Selank.
It lacks ACTH's steroid-releasing (corticotropic) activity. Animal studies report increased expression of BDNF and its receptor TrkB in the brain, effects on dopamine and serotonin systems and changes in genes related to inflammation and blood vessels after experimental stroke.
For researchers and instructors
Human evidence. Clinical studies of stroke recovery and cognitive disorders are mostly small and published in Russian. Independent randomized controlled trials are lacking.
Pharmacokinetics. Given intranasally; the intact peptide is short-lived, and some activity is attributed to fragments.
Regulatory. Approved in Russia; not FDA-approved. Since October 2026, licensed 503A pharmacies may compound it under FDA enforcement discretion, which is not approval.
Molecular identity
- Amino acids
- 7
- Molecular weight
- ~813.9 Da
- Formula
- Form-dependent; verify
- Sequence
- MEHFPGP
Sequence map
Hydropathy
Kyte–Doolittle score per residue. Positive values are water-repelling.
Origin and history
Semax was developed in the 1980s at the Institute of Molecular Genetics of the Russian Academy of Sciences in Moscow, by a team including Igor Ashmarin and Nikolai Myasoedov.
They took a fragment of the stress hormone ACTH (amino acids 4–7, Met-Glu-His-Phe) that seemed to help memory and added Pro-Gly-Pro to slow its breakdown. Semax is registered as a medicine in Russia, mainly for stroke and other brain conditions, but it is not approved in the U.S. or Europe and most studies are Russian.
Key people
- Igor AshmarinNeurochemist, Moscow
- Nikolai MyasoedovPeptide chemist, Institute of Molecular Genetics
Timeline
- 1980s
Developed in Moscow from an ACTH fragment
- 1990s–2000s
Registered and used in Russia
- 2026
FDA allows 503A compounding under enforcement discretion
See every peptide on one history timeline.
Human evidence
Some clinical reports exist, primarily from Russia; independent high-quality replication is limited.
Study design, enrollment, endpoints, outcomes and limitations must be assessed individually; registration is not proof of efficacy.
Explore the literature for Semax and distinguish in-vitro, animal, and human findings.
Safety and regulatory status
See every compound on the regulatory tracker.
Not FDA-approved as a drug in the United States.
Long-term risks, formulation differences, and human safety evidence require careful review. Educational content only; not medical advice.
Sources
Hernandez Gener, E. (2026, November 7). Semax: molecular data, research history and evidence. VALREXA Biosciences. https://valrexa.com/peptides/semax.html
APA style · Last reviewed November 7, 2026 · Our editorial standardsLast reviewed November 7, 2026. Trial and regulatory status can change; confirm in the linked registries. This profile is educational and is not medical advice, a treatment recommendation, or dosing or sourcing guidance. Report an error · Corrections policy