PeptideFederation

ACTH(4-10) analog

Semax

Also known as ACTH(4-7)-Pro-Gly-Pro, Heptapeptide Semax

Early human data

Summary

Semax is a seven-amino-acid peptide developed in Russia from a fragment of adrenocorticotropic hormone (ACTH). It is registered there as a nasal drop for ischaemic stroke and cognitive impairment. In rats it raised BDNF in the hippocampus, but rigorous Western trials have not been published.

Structure

  1. M1
  2. E2
  3. H3
  4. F4
  5. P5
  6. G6
  7. P7

HydrophobicGly / ProPolarBasic (+)Acidic (−)

ACTH(4-7) (Met-Glu-His-Phe) joined to a Pro-Gly-Pro tail that protects it from peptidases. Has no adrenal (corticotropic) activity.

How it works

Semax has no effect on cortisol. In animal studies it increases brain-derived neurotrophic factor (BDNF) and its receptor TrkB, modulates dopamine and serotonin turnover, and alters expression of genes involved in inflammation and vascular function after ischaemia.

Research use cases

Areas where Semax has been studied. Inclusion here does not mean it works for that purpose.

  • Ischaemic stroke recovery
  • Cognitive impairment
  • Optic nerve disease
  • Neuroprotection in hypoxia models

What the research found

BDNF in the hippocampus

A single intranasal dose in rats rapidly increased BDNF and TrkB expression in the hippocampus, alongside improved performance in a conditioned avoidance task.1

Clinical use in Russia

Russian reviews describe its development and clinical use for stroke and cognitive disorders. Most clinical studies are small, published in Russian-language journals and lack independent replication.2

Safety and open questions

Reported as well tolerated in Russian clinical use. No large controlled trials with systematic safety reporting are available in English.

Regulatory status

Registered in Russia as a nasal medicine for stroke and cognitive disorders. Not approved in the US or EU. Included in the July 2026 FDA advisory committee compounding vote.

Status was accurate when this page was last reviewed on October 26, 2026. Regulations change; check with the relevant authority before relying on it.

Semax: common questions

Is Semax a stimulant?

Not in the conventional sense. It does not act like amphetamine-type drugs. Its proposed effects run through neurotrophic factors and neurotransmitter modulation.

Is Semax approved for human use?

Registered in Russia as a nasal medicine for stroke and cognitive disorders. Not approved in the US or EU. Included in the July 2026 FDA advisory committee compounding vote.

References

  1. Dolotov OV, Karpenko EA, Inozemtseva LS, et al. (2006). Semax, an analog of ACTH(4-10) with cognitive effects, regulates BDNF and trkB expression in the rat hippocampus. Brain Research.
  2. Kolomin T, Shadrina M, Slominsky P, Limborska S, Myasoedov N. (2013). A New Generation of Drugs: Synthetic Peptides Based on Natural Regulatory Peptides. Neuroscience & Medicine.

Links open a PubMed search for the exact title, or the original source where one is given.