Comparison
Semax vs Selank: what are these Russian peptides, and are they legal in the US?
Neither Semax nor Selank is approved for human use in the US, and neither can be lawfully compounded today. Both are short synthetic peptides developed by Russian researchers: Semax from a fragment of the hormone ACTH, marketed for focus, and Selank from tuftsin, marketed for anxiety. FDA flagged a risk of immune reactions for both.
How do Semax and Selank compare?
| Attribute | Semax | Selank |
|---|---|---|
| Regulatory status | Research only · Not for human use | Research only · Not for human use |
| Human evidence | Animal & lab studies only | Animal & lab studies only |
| Comes as | Nasal spray (unapproved) | Nasal spray (unapproved) |
| How you get it | Not lawfully available for personal use. DiscoverMedica links to no seller. | Not lawfully available for personal use. DiscoverMedica links to no seller. |
| What it isZh Vyssh Nerv Deiat 1997Selank and short tuftsin-family peptides in adaptive behavior under stress (Neurosci Behav Physiol 2003) | A synthetic peptide built from a fragment of ACTH, a pituitary hormone | A synthetic peptide built on tuftsin, a short natural peptide |
| Marketed forThe efficacy of Semax at different stages of ischemic stroke (Zh Nevrol Psikhiatr 2018)Peptide-based anxiolytics | Focus and memory; studied in Russia after stroke | Anxiety and stress |
| FDA advisory vote, July 2026McDermott Will & Schulte | 8 to 5 to recommend a compounding route for cerebral ischemia, migraine and trigeminal neuralgia. Not binding | Not reviewed |
| FDA safety concernFDA | Possible immune reactions from aggregation and peptide impurities | The same concern |
| Key risksFDAPeptide-based anxiolytics | Not made to drug standards, so identity, purity and sterility are unverified. FDA flagged a risk of immune reactions. Nasal sprays from unregulated sellers can be contaminated. | Not made to drug standards. FDA flagged the same immune reaction risk. Lab work suggests it acts on GABA receptors, the system benzodiazepine sedatives act on, so effects could add up. |
| Listed prices | No lawful seller, so no price is listed. | No lawful seller, so no price is listed. |
Status, evidence, formats, routes and prices come from each compound’s page. Prices are the providers’ own listed starting prices, which may exclude a membership fee and change often; they are not DiscoverMedica’s prices.
What is the difference between Semax and Selank?
They come from different natural signals. Semax is built from part of ACTH, a pituitary hormone, and Russian researchers studied it for memory, attention and stroke. Selank is built on tuftsin and was studied for anxiety; lab work suggests it modulates GABA receptors and interacts with benzodiazepine binding. Peptide-based anxiolytics
A 1997 Russian review summarized 15 years of Semax research, reporting effects on memory and attention in animals and people, mostly from Russian studies. Zh Vyssh Nerv Deiat 1997
Russian animal studies of Selank and related tuftsin-family peptides reported anti-stress effects in rats and mice. Selank and short tuftsin-family peptides in adaptive behavior under stress (Neurosci Behav Physiol 2003)
What does the evidence say about Semax and Selank?
Most published research is animal and cell work from Russian groups. Clinical reports exist, such as a 2018 Russian study in which Semax after ischemic stroke raised a brain growth factor and was linked to faster functional recovery, but we found no large independent trials of either peptide for focus or anxiety in healthy people. The efficacy of Semax at different stages of ischemic stroke (Zh Nevrol Psikhiatr 2018)
Are Semax and Selank legal in the US?
Neither is FDA-approved, and neither is on the list of ingredients pharmacies may compound from. In July 2026 FDA’s advisory committee voted 8 to 5 to recommend a compounding route for Semax; Selank was not reviewed. FDA must still complete rulemaking, which could happen in 2027 or take several years. McDermott Will & Schulte
FDA has sent warning letters to online sellers of peptides that use “research use only” labels while making human-use claims. FDA warning letter
Which might suit whom: Semax or Selank?
Neither is lawfully available for personal use, and DiscoverMedica links to no seller of either. Better questions for a clinician:
- What might be behind my focus, memory or anxiety concern?
- What evidence-based treatments fit my attention or anxiety problem?
- Could a medication I take now be affecting my concentration or mood?
- Is there a clinical trial I could join?
DiscoverMedica does not recommend one over the other. Only a licensed clinician who knows your history can decide.
Looking for a lawful option?
See every compound in brain, mood & focus with its US status, evidence and risks. Only a licensed clinician who knows your history can decide what fits.
Semax vs Selank: questions, answered
Which is better, Semax or Selank?
There is no reliable answer. They are marketed for different things, focus for Semax and anxiety for Selank, and neither has been tested in large independent trials. Neither is approved for human use in the US, and products sold online are not made to drug standards, so identity, purity and sterility are unverified.
Can a clinic prescribe Semax or Selank?
Not lawfully today. Neither is FDA-approved or on the 503A list that pharmacies compound from. Semax received a favorable but non-binding advisory vote in July 2026, and FDA rulemaking would have to follow before a compounded version could be lawful. If a site offers either now, treat that as a warning sign.
Do Semax or Selank interact with other medicines?
Human interaction data are lacking. Lab research suggests Selank acts on GABA receptors and interacts with benzodiazepine binding, so it could add to the effects of sedatives. Tell a clinician about anything you take, especially sedatives or anxiety medication.
Sources
- A nootropic ACTH(4-10) analog, Semax: 15 years of design and study (Zh Vyssh Nerv Deiat 1997)
- The efficacy of Semax at different stages of ischemic stroke (Zh Nevrol Psikhiatr 2018)
- Selank and short tuftsin-family peptides in adaptive behavior under stress (Neurosci Behav Physiol 2003)
- Peptide-based anxiolytics: molecular aspects of Selank activity (Protein Pept Lett 2018)
- FDA: Bulk drug substances that may present significant safety risks (Category 2)
- McDermott Will & Schulte: PCAC backs majority of peptides in two-day public meeting (July 2026)
- FDA: Pharmacy Compounding Advisory Committee, July 23-24, 2026
- FDA warning letter: Peptide Partners (Aug 24, 2026)
- PubChem: Semax (CID 9811102)
- PubChem: Selank (CID 11765600)
Last reviewed October 7, 2026. Every source above was checked on or before that date. Educational information only, not medical advice; it does not replace a conversation with a licensed clinician. DiscoverMedica does not employ clinicians.