Brain & sleep Nootropic peptide (ACTH(4-10) analog)
Semax
Regulatory status
Status at a glance
503A compounding status
Advisory committee voted to include
FDA’s Pharmacy Compounding Advisory Committee (PCAC) voted in favor of adding this substance to the 503A bulks list. PCAC votes are non-binding recommendations; FDA and HHS make the final decision, and the substance is not on the bulks list unless FDA adds it.
- FDA approval
- Not FDA-approved for any use
- 503B outsourcing
- Not determined
- Anti-doping (WADA)
- Not on the WADA Prohibited List
- DEA schedule
- Not a controlled substance
About peptide status
Most peptides discussed here are not FDA-approved for any use, and products labeled “research use only” are not for human use. Removal from Category 2 does not authorize compounding. PCAC votes are non-binding recommendations; FDA and HHS make the final decisions.
This is not medical or legal advice, and we do not publish dosing, sourcing or reconstitution information. Talk with a licensed clinician before using any peptide.
If you think you are having a medical emergency, call 911.
Key takeaway
Semax is a synthetic nootropic peptide developed in Russia, where it is approved for stroke and cognitive conditions, and sold elsewhere on the "research peptide" market for cognition. The human evidence is limited to small, mostly Russian studies not independently replicated to Western standards. As of 2026 it is not FDA-approved, though a 2026 FDA advisory committee gave a non-binding favorable vote toward allowing it to be compounded.
At a glance
- FDA status
- Not FDA-approved, sold in the wellness/gray market, and approved in Russia
- What it is
- Synthetic peptide based on a fragment of the hormone ACTH
- Research
- Human evidence limited to small, mostly Russian studies; a 2026 FDA advisory vote was favorable but non-binding
- How it's taken
- Typically used intranasally where it is marketed
- Evidence strength
- Low research
Summary
Semax is a synthetic peptide approved in Russia but not by the FDA. See how it is thought to work and what the limited human research shows.
What is semax?
Semax is a synthetic seven-amino acid peptide based on a fragment of ACTH (adrenocorticotropic hormone), with added amino acids for stability. It was developed by Russian research institutes and is approved in Russia for stroke and cognitive and neurological conditions. Outside Russia it is sold through wellness and "research peptide" channels for cognition and neuroprotection, and it is not an approved medicine in the United States.
How does it work?
Semax is proposed to act as a nootropic and neuroprotectant by increasing levels of nerve-growth signals such as BDNF and NGF and modulating brain chemical systems. These effects are reported mainly in animal and laboratory studies. This describes the proposed mechanism, separate from demonstrated benefit in people.
Is it FDA-approved?
Safety note
Status: Not FDA-approved, sold in the wellness/gray market, and approved in Russia
Category: Wellness and performance · Primary body area: Brain & sleep
No. Semax is not approved by the FDA. As neutral regulatory facts: it is approved in Russia for stroke and cognitive indications; and in July 2026 the FDA's Pharmacy Compounding Advisory Committee gave semax a non-binding favorable advisory vote toward allowing it to be compounded under 503A, while FDA staff opposed it citing insufficient evidence. An advisory vote is only a recommendation; it does not make semax approved, and FDA rulemaking would still be required.
What does the research show?
Editor’s note
Evidence strength: Low research
Mechanistic and animal support exists alongside small, non-independent Russian human studies, but there is no regulatory-grade human efficacy evidence, and the 2026 advisory vote was non-binding and opposed by FDA staff.
There is some human evidence, but of limited quality. Russian studies have reported use in stroke, transient ischemic attack, cognitive disorders, and optic conditions, but the trials are generally:
- Small
- Methodologically weak
- Single-country
- Often developer-affiliated, with little independent replication
An analytical review notes these peptides have not completed clinical trials to Western standards. The evidence does not establish efficacy by those standards.
What is the difference between semax and selank?
Semax and selank are both synthetic seven-amino acid peptides developed by Russian research institutes, and the main difference is the natural molecule each is based on and the use each is approved for in Russia, as the table shows:
| Attribute | Semax | Selank |
|---|---|---|
| Based on | A fragment of the hormone ACTH | Tuftsin, a natural immune-modulating peptide, as a stabilized analog |
| Approved in Russia | For stroke and cognitive and neurological conditions | As an anti-anxiety agent |
| Proposed mechanism | Raises nerve-growth signals such as BDNF and NGF | Acts on the brain's enkephalin and GABA systems and on serotonin metabolism |
| U.S. compounding review | In July 2026 an FDA advisory committee gave a non-binding favorable vote toward allowing it to be compounded, which FDA staff opposed | Not among the peptides reviewed favorably |
Both mechanism descriptions come mainly from animal and laboratory work, and neither has been shown to produce a benefit in people.
Neither peptide is FDA-approved. An advisory vote is only a recommendation, and it does not make semax approved.
The human evidence for both is limited in the same way: small, mostly Russian studies, often run by the developing institutions and not independently replicated. An analytical review notes that such peptides have not completed clinical trials to Western regulatory standards. The evidence does not establish that either one works or that one works better than the other.
Sources: a preclinical study of semax (Glazova et al., Neuropeptides, 2020, DOI: 10.1016/j.npep.2020.102114) and an analytical review of research peptides (Esposito et al., Drug Testing and Analysis, 2020, DOI: 10.1002/dta.2717), indexed on PubMed; and reporting on the July 2026 FDA advisory committee vote. This document is educational, is not medical advice or a health claim, and is not an offer to sell any product.
Registered human trials
0 registered human trials on ClinicalTrials.gov that we reviewed
Sources
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- [2]
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- [4]
- [5]
- [6]
- [7]
- [8]
- [9]
- [10]
- [11]
- [12]
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