# Semax

A nasal peptide developed in Russia, where it is registered for stroke and other brain conditions. Outside Russia it is sold as a focus and memory booster. Nearly all the human research is Russian and falls short of modern trial standards.

Also called: ACTH 4-10 analog
Source page: https://peplogue.com/peptides/semax/
Updated: 2026-10-22. Not medical advice.

## How it works

- Where it acts: The exact target is unclear. It is thought to raise BDNF, a brain growth factor, and to act on melanocortin receptors.
- What it changes: In animals, more BDNF and better survival of nerve cells after stroke.
- What people notice: Users report sharper focus. The evidence is mostly from Russian studies.

## What the evidence shows

- **Focus and memory in healthy people**: Lab only. No controlled trials found.
- **Recovery after stroke**: Early. Thirteen Russian studies cover about 1,000 patients, all as an add-on to usual care and mostly without clear randomization or blinding. A 2018 analysis could pool only three of them.
- **Anxiety and low mood**: Lab only. No controlled trials found.

## Side effects and risks

- unknown: Studies report no significant side effects but do not say how they collected them.
- unknown: FDA cites the risk of immune reactions, clumping and impurities in compounded versions.

Who should avoid it: Treat it as untested outside its approved uses in Russia.

## How it has been given in studies

As nose drops. Stroke studies used a 1% solution for 5 to 21 days. Recovery studies used a 0.1% or a 1% solution.

## Legal status

- United States: undefined. Advisers backed compounding in July 2026. FDA staff opposed it, and FDA had not acted by late September 2026.
- European Union: undefined
- Spain: undefined. No semax medicine in CIMA. Not authorised in Spain and not lawful to sell to the public.
- Germany: undefined. Not approved in Germany. Selling it as a medicine without approval is a crime (AMG § 21, § 96); sold online only as 'research' products.
- France: undefined. No French authorisation found. Not named by ANSM, but its Jul 2026 alert says peptides bought outside the official circuit are illegal.
- Italy: undefined. No Italian authorisation found. Not lawful to sell to the public as a medicine. Research-grade vials online are unverified products.
- Netherlands: undefined. No Dutch marketing authorisation found. Selling it as a medicine without one is illegal per IGJ, even if labelled 'research use'.
- United Kingdom: undefined
- Canada: undefined
- Australia: undefined

## Questions people ask

**Does Semax improve focus and memory?**

No controlled trials in healthy people were found. Users report sharper focus for a few hours, which is hard to tell from expectation without a placebo.

**What is Semax approved for?**

It is registered in Russia for stroke and other brain conditions. Thirteen Russian stroke studies cover about 1,000 patients, mostly without clear randomization or blinding.

**What are the side effects of Semax?**

Studies report no significant side effects but do not say how they collected them. Users report irritability or anxiety and nose irritation, and FDA cites the risk of immune reactions and impurities in compounded versions.

**Is Semax legal in the US?**

FDA advisers voted 8 to 5 in July 2026 to back compounding, but FDA staff opposed it and FDA had not acted by late September 2026.

## Sources

- 2024 review of Semax studies in stroke (Korsakov Journal): https://www.mediasphera.ru/issues/zhurnal-nevrologii-i-psikhiatrii-im-s-s-korsakova-2/2024/8-2/1199772982024082056
- 2018 Russian meta-analysis of Semax in stroke: https://www.vvmr.ru/en/archives/2018/2-84-aprel-2018/tekhnologii-vosstanovitelnoy-meditsiny-i-meditsinskoy-reabilitatsii/2018-84-metaanaliz-effektivnost-semaksa-v-ostrom-periode-ishemicheskogo-insulta.html
- McDermott: July 2026 advisory committee votes: https://www.mcdermottlaw.com/insights/bulk-list-bound-pcac-backs-majority-of-peptides-in-two-day-public-meeting/