Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Head-to-head comparison of Semax and Selank — mechanism, side effects, legal status, and pricing.
Semax is a synthetic heptapeptide (Met-Glu-His-Phe-Pro-Gly-Pro) derived from ACTH(4-10) with a Pro-Gly-Pro C-terminal extension for metabolic stability. It was developed at the Institute of Molecular Genetics (Russian Academy of Sciences) and registered as a drug in Russia in 1994. It is not FDA-approved.
Selank is a synthetic heptapeptide analog of the endogenous immunomodulatory tetrapeptide tuftsin, extended with a Pro-Gly-Pro C-terminus for metabolic stability. Developed at the Institute of Molecular Genetics (Russian Academy of Sciences), it is registered as an anxiolytic drug in Russia but is not approved by the FDA or EMA.
Semax
Selank
Category
Legal Status
Mechanism
Half-life
Side Effects
COA-verified vendors · trust score ≥70 required · single-vial price — bulk/bundle deals may be lower
Semax
Selank
COA corpus from Disclosed Labs — independently tested batches only.
Semax
82
COAs
99.5%
Avg purity
16
Labs
Selank
81
COAs
99.6%
Avg purity
18
Labs
Selank is among peptides under FDA review for the Category 1 (503A) list; if added, it would require a prescription to be compounded by registered 503A/503B pharmacies — not yet authorized. Semax remains research-only. In April 2026 the FDA removed 12 peptides from Category 2, which does not place them on the Category 1 list or authorize compounding. The FDA's Pharmacy Compounding Advisory Committee is advisory and meets July 23–24, 2026 to review nominations and make recommendations to the FDA.
Semax's evidence base is primarily Russian-language clinical literature. Gusev, Skvortsova and colleagues reported improved neurological recovery in acute hemispheric ischemic stroke when Semax was added to conventional therapy (Zh Nevrol Psikhiatr, 1997; PMID 11517472), and subsequent Russian studies extended use to cerebrovascular insufficiency (PMID 15792140). Preclinical work by Dolotov, Myasoedov and colleagues demonstrated that intranasal Semax rapidly elevates BDNF protein and TrkB activation in rat hippocampus and basal forebrain (Brain Res 2006, PMID 16996037; J Neurochem 2006, PMID 16635254). Genome-wide transcriptional analysis by Medvedeva et al. in rat focal ischemia showed Semax modulates a broad panel of immune-response and vascular-system genes (BMC Genomics 2014, PMID 24661604). Western evidence is limited; Semax has not been evaluated by the FDA and has no pivotal trials in the US or EU.
Key references
Selank's clinical evidence base is almost entirely Russian. Zozulia et al. (2008, Zh Nevrol Psikhiatr Im S S Korsakova; PMID 18454096) compared selank to medazepam in 62 patients with generalized anxiety disorder and neurasthenia, reporting comparable anxiolytic efficacy plus antiasthenic/psychostimulant effects, together with changes in serum enkephalin-degrading enzyme activity. Mechanistic work includes Inozemtseva et al. (2008, Dokl Biol Sci; PMID 18841804) showing intranasal Selank increases hippocampal BDNF mRNA and protein in rats, Volkova et al. (2016, Front Pharmacol; PMID 26924987) demonstrating modulation of GABAergic gene expression, and Vyunova et al. (2018, Protein Pept Lett; PMID 30255741) proposing a positive allosteric GABA-A mechanism. No US or EU regulatory clinical trials have been conducted; safety data outside Russia is limited.
Semax and Selank are both in the Cognitive category and may have overlapping mechanisms. Researchers should review both profiles carefully, understand the mechanisms of action, and monitor the relevant biomarkers when combining compounds in the same class. As always, consult a licensed healthcare provider before making any decisions about combining research compounds.
This platform provides informational tools only, not medical advice. This comparison is for educational purposes only. Consult a licensed provider.
Contraindications
Lab Testing
Key references
Disclosed Labs