Reviewed evidence dossier / SMX-01
Semax evidence:
older records, clearly bounded.
Two older, region-specific human records report observations in stroke populations. A separate rat ischemia experiment reports changes in neurotrophin-related gene transcription. This dossier keeps those records distinct from healthy-person cognition claims, catalog identity, and unresolved safety questions.
Specific observations in defined stroke records.
The cited human reports describe clinical, functional, electrophysiological, motor, and plasma-BDNF observations in their own post-stroke populations. The cited animal study describes gene transcription in a rat ischemia model.
General cognitive effects, catalog equivalence, or settled safety.
It does not establish outcomes in healthy people, broad neurological conclusions, long-term safety, equivalence among free-base and acetate forms, or a final U.S. regulatory determination.
What kind of answer can this dossier provide?
Semax has published human records, but they are not a modern, broad evidence base. The two cited human reports are older Russian-language studies in stroke populations, while the mechanistic paper is a rat cerebral-ischemia experiment. Together they justify precise questions about those records—not a general conclusion about cognition, attention, memory, or long-term safety.
“Semax” is not specific enough without chemical form.
PubChem CID 9811102 describes the heptapeptide H-Met-Glu-His-Phe-Pro-Gly-Pro-OH, sequence MEHFPGP. FDA’s 2026 briefing separately evaluates Semax free base and Semax acetate and notes inconsistent naming across nominations, references, and commercial materials.
A name match does not establish whether a paper, regulatory record, or catalog vial concerns the free base, an acetate salt, another derivative, or an analytically equivalent material. Exact sequence, form, formulation, and analytical identity remain separate questions.
Finding, model, limitation, source.
COMPARATIVE
1997 acute-stroke record
A Russian-language report compared 30 participants receiving Semax as part of combined care with 80 control participants receiving conventional care. The report used clinical rating scales, EEG mapping, and somatosensory evoked-potential measurements and described differences in the course of neurological recovery.
Limit: The indexed abstract does not provide the blinding, allocation, attrition, or statistical detail expected from a modern confirmatory trial. It cannot establish broad neurological or cognitive outcomes.
CLINICAL
2018 rehabilitation-stage and plasma-BDNF observations
A Russian-language study followed 110 post-stroke participants divided by earlier or later rehabilitation timing and by Semax exposure. It recorded plasma BDNF, motor performance, and Barthel index scores and reported changes and correlations across those groups.
Limit: The record combines rehabilitation timing, exposure groups, biomarker changes, and functional measures. It does not establish a healthy-person cognitive effect, isolate every contributor to recovery, or provide broad long-term safety evidence.
ISCHEMIA MODEL
Neurotrophin-related gene transcription
Researchers examined rat brains after permanent middle cerebral artery occlusion and reported that Semax and Pro-Gly-Pro altered transcription of neurotrophins and their receptors in rat cortex.
Limit: Gene transcription in a rat ischemia model is not a demonstrated human cognitive, functional, or safety outcome.
STAFF REVIEW
Identity, quality, and evidence questions remain open
FDA’s July 2026 briefing evaluated Semax free base and Semax acetate for a compounding-list advisory process. The document distinguishes the two substances, identifies inconsistent naming and characterization issues, and reviews a limited clinical record.
Limit: A staff briefing and advisory-committee process are not a final FDA determination. Advisory recommendations are non-binding.
SAFETY GAP
Limited information does not resolve risk
FDA’s public safety-risk page says compounded Semax may pose immunogenicity risk for certain routes because of potential aggregation and peptide-related impurities, and that the agency has no or limited safety information for proposed routes.
Limit: This is an identified information and quality gap. It is neither proof that every Semax material causes harm nor evidence that a separate material is safe.
Questions the cited record does not answer.
The cited human studies are older and region-specific. The ledger does not contain a large, independently replicated, modern multicenter record.
Stroke-population findings and rat ischemia experiments do not establish attention, memory, focus, or other outcomes in healthy people.
The cited reports and FDA records do not resolve uncommon harms, immunogenicity, product impurities, or long-term exposure.
Free base, acetate salt, formulation, and catalog identity cannot be treated as interchangeable without analytical evidence.
The July 2026 PCAC materials document an advisory process. Current legal and regulatory status must be checked in live FDA records.
No cited source verifies the identity, purity, stability, safety, efficacy, approval, or intended use of PSC or another supplier’s material.
What the cited record can—and cannot—answer.
What is Semax?
PubChem describes Semax as the heptapeptide MEHFPGP. FDA’s 2026 briefing distinguishes Semax free base from Semax acetate and notes that published and commercial naming is not always specific enough to identify which material is being discussed.
Is there human evidence for Semax?
Yes, but the cited human record is older, region-specific, and limited: a 1997 comparative study in acute-stroke care and a 2018 rehabilitation-stage study in 110 post-stroke participants. Neither establishes broad cognitive outcomes or long-term safety.
What did the 2018 human study measure?
It recorded plasma BDNF, motor performance, and Barthel index scores across earlier- and later-rehabilitation groups with and without Semax exposure. Those measures do not establish a healthy-person cognitive outcome.
Does the rat gene-expression study establish a human cognitive outcome?
No. It reports neurotrophin and receptor gene transcription in a rat cerebral-ischemia model. A molecular change in that model is not a demonstrated human cognitive, functional, or safety outcome.
Was the July 2026 FDA briefing a final FDA determination?
No. The briefing was prepared for an advisory-committee process. FDA states that advisory recommendations are non-binding and that the agency makes the final determination after its review is complete.
Does this dossier evaluate any PSC catalog vial?
No. Published or regulatory records for a named material do not establish the identity, equivalence, purity, safety, efficacy, approval, or intended use of a separate catalog material.
Open the source and preserve its boundary.
- Gusev et al. · Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova · 1997Russian-language comparative clinical report in acute hemispheric ischemic stroke; 30 Semax participants and 80 conventional-care controls.PubMed 11517472 ↗
- Gusev et al. · Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova · 2018Russian-language 110-participant post-stroke record examining rehabilitation timing, plasma BDNF, motor measures, and Barthel index scores.PubMed 29798983 ↗
- Dmitrieva et al. · Cellular and Molecular Neurobiology · 2010Neurotrophin and receptor gene transcription after permanent middle cerebral artery occlusion in rats; not a human outcome study.PubMed 19633950 ↗
- PubChem · Compound CID 9811102Public identity record for ACTH(4-7)-Pro-Gly-Pro, sequence MEHFPGP. A database identity does not verify a supplier’s material.PubChem record ↗
- FDA Pharmacy Compounding Advisory Committee briefing · July 2026FDA staff evaluation of Semax free base and Semax acetate for a 503A compounding-list advisory process; the document expressly precedes final agency action.FDA briefing PDF ↗
- FDA PCAC meeting record · July 23–24, 2026Official agenda, materials, and explanation that advisory recommendations are non-binding.FDA meeting record ↗
- FDA compounded-substance safety-risk pageLive agency record describing aggregation, peptide-related impurity, immunogenicity, and limited safety-information concerns for compounded Semax.FDA safety-risk record ↗
Versioned, not silently rewritten.
Version 1.0 published. Added claim-linked human, animal, identity, FDA, and FAQ records; made the age, language, design, material-form, catalog-equivalence, and advisory-status limits explicit.
A substantive correction records the date, changed statement, reason, and supporting source. Send a precise citation or correction request through the PSC policies and contact page.