VialOwlLibrary / Cognitive
Semax
Also known as ACTH (4-7) Pro-Gly-Pro, Heptapeptide Semax
Human trials
Synthetic peptide derived from a fragment of ACTH, registered in Russia for stroke and other neurological conditions. Evidence is mainly small Russian clinical studies and animal research.
Not an approved medicine. Semax is not an approved medicine for this use in Australia or the United States. This page summarises published research for information only. It is not a recommendation to use Semax, and VialOwl does not sell or supply it.
Background
Synthetic peptide made by joining a fragment of the pituitary hormone ACTH (positions 4 to 7) to a stabilising Pro-Gly-Pro tail. Developed in Moscow at the Institute of Molecular Genetics of the Russian Academy of Sciences and registered in Russia for stroke and other brain conditions.
How it is thought to work
It is designed to keep some brain effects of ACTH fragments without stimulating the adrenal glands. Animal studies show changes in brain derived neurotrophic factor (BDNF) and in genes linked to inflammation and blood vessels after brain injury.
What is claimed, and the evidence
| Claim | Evidence | Notes |
|---|---|---|
| Improves recovery after ischaemic stroke | Small human studies | Russian studies of 30 to 110 patients, not blinded or placebo controlled; published mainly in Russian. |
| Improves memory, focus and mental performance (nootropic) | No published evidence | Heavily marketed online; human evidence in healthy people is limited to a small brain imaging study that did not measure thinking outcomes. |
| Antidepressant and anti stress effects | Animal studies only | Rat models only. |
| Protects nerves in optic nerve disease, glaucoma or ADHD | No published evidence | Mentioned in Russian clinical use and online claims; no rigorous published trials found. |
Side effects
| Effect | How often | Notes |
|---|---|---|
| Side effects poorly documented | Frequency unknown | The published Russian studies report little on adverse events, and no large controlled trials exist. |
| Nasal irritation | Frequency unknown | Plausible with nasal use; no reliable frequency data. |
| Immune reactions to impurities or aggregates Serious | Frequency unknown | FDA flags possible immunogenicity from aggregation and peptide related impurities, and says it has little or no safety information for proposed routes. |
Warnings
- No large placebo controlled trials; evidence comes from small Russian studies and animal work.
- FDA listed semax among bulk substances that may present significant safety risks because it lacks human safety information; an advisory committee vote in 2026 has not been finalised.
- Unapproved products are not made to medicine standards and may be contaminated, underdosed, overdosed or contain a different substance from the label; the TGA warns that injected unapproved peptides carry risks including contamination, infection and local tissue damage.
Regulatory status
- Australia
- Not included on the ARTG (unapproved). Not specifically listed in the Poisons Standard (June 2026).
- United States
- Not FDA approved. Nomination withdrawn and removed from 503A Category 2 in April 2026. In July 2026 an FDA advisory committee voted 8 to 5 to recommend it for the 503A bulks list; FDA has not finalised this.
Sources
- The efficacy of semax in the treatment of patients at different stages of ischemic stroke
- Effectiveness of semax in acute period of hemispheric ischemic stroke
- Antidepressant-like and antistress effects of the ACTH(4-10) synthetic analogs Semax and Melanotan II on male rats
- FDA: Certain bulk drug substances for use in compounding that may present significant safety risks
- TGA: Understanding your responsibilities when importing, compounding and supplying unapproved peptide products
- FDA: Pharmacy Compounding Advisory Committee meeting, 23 to 24 July 2026
Also in Cognitive
From the VialOwl library, reviewed 26 September 2026. For education and general information. It is not medical advice and not a recommendation to use Semax.