ACTH (4-10) analog

Semax

Preclinical

A nootropic ACTH fragment used clinically in Russia for stroke.

Cited sources: 1
Human-tested claims: 0 of 2
Best evidence: Tier 3 · Preclinical
Status: Approved abroad

A short peptide derived from ACTH, studied for neuroprotection and cognition and used clinically in Russia (including in stroke). It modulates BDNF and dopamine signaling; the mechanism work is Western-indexed, but the clinical efficacy data is overwhelmingly Russian and unreplicated abroad.

neuronootropicfrontier

How it works

Semax is ACTH(4-7) with a Pro-Gly-Pro tail that removes the hormone activity and adds stability. In animal work it raises BDNF and TrkB signaling — pathways tied to neuron survival and plasticity — the mechanistic basis for its nootropic and neuroprotective reputation.

Sequence: MEHFPGPACTH(4-7) (Met-Glu-His-Phe) plus a stabilizing Pro-Gly-Pro tail.

What it's studied for

One claim per card, each with its own tier and source. Tiers 1 and 2 are human data. Tiers 3 and 4 are not yet.

Regulated BDNF and TrkB expression in rat hippocampus — the mechanistic basis for its nootropic claims.
Preclinical
[1]Dolotov et al., 2006 (Neuroscience)(opens in a new tab)
Neuroprotective and pro-cognitive effects reported in Russian clinical studies; not independently replicated in Western RCTs.
Emerging

Regulatory & legal status

Approved abroad

Registered in Russia as an intranasal drug for cognitive/cerebrovascular indications and stroke. Not approved by the FDA or EMA.

[1]Dolotov et al., 2006 (Neuroscience)

Frequently asked

Is Semax an approved stroke treatment?

In Russia it is used clinically, including in stroke care. It has not been approved or validated in large Western randomized trials.

References

[1]Dolotov et al., 2006 (Neuroscience) (opens in a new tab)

Written by Twenty Residues editorial. Medical review: pending; a named reviewer is being assigned.

Last updated September 19, 2026.

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Update history

2026-09-19 — Sourced review — every claim checked against primary literature; sequence, regulatory status, safety, and FAQs added.