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Semax: What the Evidence Shows and Where It Stands
Semax is not FDA-approved. What FDA reviewed, what studies in people exist, the HHS interim policy's narrow coverage, and the safety questions.
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Quick facts
Fact sheet
- U.S. status
- Strongest evidence
- Limited human data
- Status verified
Semax is marketed online as a “nootropic,” and it is a registered drug in another country. In the United States it is not approved, FDA reviewed it for three conditions that are not memory or focus, and a new HHS policy covers one narrow form of it.
Key takeaways
- Semax is not FDA-approved for any use. FDA says it is a registered drug in Russia, sold as nasal drops. That is not U.S. approval.
- FDA did not review semax for memory or concentration. It reviewed three uses: cerebral ischemia, migraine and trigeminal neuralgia. For all three, it found “insufficient evidence of effectiveness.”
- We found no controlled trial showing that semax improves cognition. A search of ClinicalTrials.gov for “semax” returned no studies on Nov. 3, 2026.
- HHS’s Oct. 30, 2026 interim policy covers only one form: semax free base, given intranasally. It does not cover the acetate form or injection. It is not FDA approval.
- Safety data are limited. FDA raised questions about bleeding, abuse potential and immune reactions, and described an adverse event report involving hospitalization.
What is semax, and is it approved?
Semax is a peptide that FDA describes as a registered drug in Russia, sold as nasal drops (FDA). It has no FDA approval, and we found no application for it in FDA’s Drugs@FDA data. A registration in another country is not evidence reviewed by FDA, and we have not reviewed Russia’s regulatory documents.
What did FDA review?
In July 2026, FDA’s drug center proposed not adding semax to the compounding list, and FDA presented its review to the Pharmacy Compounding Advisory Committee (FDA presentations; briefing document; CDER proposal). The committee voted 8 to 5, with 1 abstention, in favor of listing it, according to a law-firm account (secondary source).
FDA evaluated semax for cerebral ischemia (reduced blood flow to the brain), migraine and trigeminal neuralgia. It did not evaluate it for memory or concentration. FDA also did not consider seven Russian-language articles on ischemia because they lacked complete references in English. Those articles may contain evidence that neither FDA nor we evaluated. The careful statement is therefore not “no evidence exists” but that FDA found insufficient evidence in what it reviewed.
What studies in people exist?
We read these studies through FDA’s description, not the originals.
| Type | Study | People | What was found |
|---|---|---|---|
| Open-label, no comparison group | Koroleva 1996, pain | 37 | Migraine pain stopped in 4 of 12 people; no change in typical neuralgia. FDA said it was not effective for most |
| Conference abstract | Cherkasova 2002, chronic ischemia | not stated | Changes in blood-clotting lab tests; no measure of brain function |
| Healthy volunteers | Kaplan 1996; Lebedeva 2018; Panikratova 2020 | 19, 14, 14 | Healthy people, so they don’t test treating a condition; the last two may include the same participants |
| Abstracts | Children with depression; children with tics; an ulcer study | 120, 331, 32 | Incomplete information; sometimes combined with other treatments |
| Animal | Rats | — | Reaches the brain through the nose; breaks down quickly |
Source: FDA presentations and briefing document. None of these is a controlled trial of cognition, and the controlled evidence for the three reviewed uses was judged insufficient. Our guide to peptides for cognitive function puts semax next to selank.
How do FDA and HHS treat it for compounding?
| Status | Source | |
|---|---|---|
| FDA approval | None. No application found | FDA |
| FDA 503A list | Not listed (list updated May 14, 2026) | FDA list |
| FDA Category 2 (“may present significant safety risks”) | In it from Sept. 29, 2023; out since April 22, 2026, when the nomination was withdrawn. FDA’s page still describes immune-reaction and impurity risks | FDA |
| HHS interim policy (Oct. 30, 2026) | Covered under conditions, one form only: semax free base, intranasal, a single active ingredient and a patient-specific prescription, among other conditions. Not the acetate form, not injection, not blends | Federal Register |
| HHS comment period | Open; closes 11:59 p.m. Eastern on Nov. 13, 2026 | docket |
What the HHS policy means: HHS said it does not intend to take enforcement action against state-licensed pharmacies, federal facilities and licensed physicians that compound this form of semax under section 503A, as long as all of the policy’s conditions are met. That is enforcement discretion, not approval. FDA does not review compounded drugs for safety, effectiveness or quality before they are marketed. HHS may revisit the policy.
Before the policy was issued, boards in Alabama and Mississippi told licensees they may not compound, administer or dispense non-FDA-approved or research-grade peptides. We found no update from them as of Nov. 3, and it isn’t clear how those notices apply to compounding under the HHS policy.
Where do HHS and FDA’s reviewers disagree?
We present both and do not choose.
| Question | HHS (policy) | FDA (documents above) |
|---|---|---|
| Safety record | “several hundred subjects with no reported adverse outcome” | Safety data insufficient; abstracts incomplete; one adverse event report involved hospitalization |
| Bleeding and abuse concerns | They “have no clinical counterpart” | Not studied enough to rule out; absence of evidence is not absence of risk |
| Route | Covers only the nasal form | Evaluated the proposed nasal spray and subcutaneous injection |
What are the risks?
- Limited safety data. FDA calls safety “insufficient” by the nasal route, with no data by subcutaneous injection and no human pharmacokinetic data (FDA).
- Bleeding. FDA raised a concern about a possible antithrombotic effect, especially with a bleeding risk or drugs that raise it. It is based on lab changes in an abstract and on rat data; FDA did not describe bleeding cases in what we read.
- Abuse potential. FDA says neither the nominators nor FDA identified nonclinical studies showing whether semax is reinforcing or addictive.
- Immune reactions. FDA says semax may pose a risk of immune reactions, and cites injection and nasal spray.
- A reported case. An adverse event report from May 2025 described eye pain and burning after nasal drops bought online, with hospitalization and symptoms lasting at least a year. FDA notes that this reporting system has limitations. We do not name the seller.
- Long-term safety, interactions and dependence: we found no data.
Which claims are not supported?
- “Clinically proven nootropic,” or “boosts memory and focus.” FDA did not evaluate semax for that, and we found no controlled trial.
- “Approved in Russia, so it’s proven.” A registration in another country is not evidence reviewed by FDA.
- “No side effects.” Not shown.
- “It’s legal now” or “FDA approved.” Neither. HHS’s policy is interim enforcement discretion, for one form, under conditions.
What should you ask your doctor?
- What is behind my concern about memory, focus or migraine, and what are the evidence-based options?
- If semax is suggested, for which condition, what human evidence supports it, and who makes it?
- Could it interact with medicines I take, especially those that affect bleeding?
- What would tell us it is helping, and when would we stop?
We do not give doses, cycles or preparation instructions, and we do not recommend sellers.
Frequently asked questions
Is semax FDA-approved?
No. FDA says it is a registered drug in Russia, which is not U.S. approval.
Does semax improve memory or focus?
FDA did not evaluate it for memory or focus, and we found no controlled trial showing that it does.
Is semax legal in the US?
It is not FDA-approved. On Oct. 30, 2026, HHS said it does not intend to take enforcement action against certain compounding of semax free base given intranasally, under conditions, on an interim basis. That is not an approval or a legalization, and state notices are separate.
Is semax the same as selank?
No. They are different peptides. Selank is not among the six peptides in HHS’s policy. See our guide to peptides for cognitive function.
From Best Peptides Today
Sources we checked
- FDA presentations to the Pharmacy Compounding Advisory Committee on semax (July 24, 2026)FDA. Accessed .
- FDA briefing document on semaxFDA. Accessed .
- FDA CDER proposal on seven peptides (July 2026)FDA. Accessed .
- FDA 503A Category 1 list (updated May 14, 2026)FDA. Accessed .
- FDA: bulk drug substances that may present significant safety risks (Category 2)FDA. Accessed .
- Federal Register: HHS enforcement discretion policy on 503A peptide compounding (Oct. 30, 2026)Other. Accessed .
- HHS: Enforcement Discretion Policy, with Appendices A and BOther. Accessed .
- Regulations.gov docket HHS-OASH-2026-0496Other. Accessed .
- McDermott+: PCAC votes on peptides (secondary source)Other. Accessed .
- ClinicalTrials.gov search for semax (0 studies, Nov. 3, 2026)ClinicalTrials.gov. Accessed .
- Alabama Board of Medical Examiners: notice on prescribing non-FDA-approved research-grade peptidesOther. Accessed .
- Mississippi nursing, pharmacy and medical licensure boards: joint statement on peptides (Aug. 19, 2026)Other. Accessed .
Written and maintained by the Best Peptides For Editorial Team. How we rate evidence.