Combination evidence
Selank + Semax
Also called Russian nootropic stack, Selank/Semax
Selank and Semax are synthetic heptapeptides developed in Russia, where a peer-reviewed review lists both among registered peptide drugs (Selank as an anxiolytic, Semax as a nootropic) 7. Neither is FDA-approved. No human study giving them together was found; one fMRI study gave each separately to healthy volunteers 1.
Not studied together in humans
Components
A pre-mixed product with these contents has its own page: Selank + Semax Blend.
What has been studied
- No human study of Selank and Semax given together was found. Searched: PubMed (selank AND semax; semax AND selank AND human) and ClinicalTrials.gov (selank; semax), October 2026.
- In a resting-state fMRI study of 52 healthy participants, each person received Semax, Selank or placebo (not both); the authors reported general and specific effects of each peptide on connectivity between the right amygdala and right temporal cortex 1.
Why the pairing is discussed
Mechanistic reasoning drawn from studies of each component. Theoretical unless a study above tested the pair.
- Theoretical: in brain-cell membrane assays, Selank acted as a positive allosteric modulator of GABA binding 2, and in patients with generalized anxiety disorder its effects were compared with medazepam 3.
- Theoretical: Semax bound rat basal-forebrain membranes and increased BDNF protein there after intranasal application 4. The pairing is discussed as combining an anxiolytic and a nootropic profile.
Concerns and unknowns
- Overlap: in human serum in vitro, both Semax and Selank inhibited enkephalin-degrading enzymes 5, so the two may act on a shared pathway; combined effects have not been measured.
- In membrane assays, Selank's combined action with benzodiazepines on GABA binding was not cumulative and Selank blocked the modulatory activity of diazepam 2; interactions with other CNS-active drugs are poorly characterised.
- FDA lists Selank acetate and Semax among nominated-but-withdrawn compounding substances that may present significant safety risks, citing possible immunogenicity and missing or limited safety information 6.
- Russian registration is reported in a 2022 review 7; the Russian state register itself was not accessed.
- Neither is named on WADA's 2026 list; because they lack approval outside Russia, athlete status under section S0 should be confirmed with the relevant anti-doping organisation 8.
Status of each component
Frequently asked questions
Has Selank + Semax been studied together?
Are they approved?
Do they share a mechanism?
Both inhibited enkephalin-degrading enzymes in human serum in a laboratory study 5, so effects could overlap.
Can they interact with other drugs?
Are they allowed in sport?
References
- Functional Connectomic Approach to Studying Selank and Semax Effects Dokl Biol Sci. 2020
- Peptide-based Anxiolytics: The Molecular Aspects of Heptapeptide Selank Biological Activity Protein Pept Lett. 2018
- Efficacy and possible mechanisms of action of a new peptide anxiolytic selank in the therapy of generalized anxiety disorders and neurasthenia (in Russian) Zh Nevrol Psikhiatr Im S S Korsakova. 2008
- Semax, an analogue of adrenocorticotropin (4-10), binds specifically and increases levels of brain-derived neurotrophic factor protein in rat basal forebrain J Neurochem. 2006
- Semax and selank inhibit the enkephalin-degrading enzymes from human serum (in Russian) Bioorg Khim. 2001
- Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks (content current as of 04/22/2026) FDA. 2026
- Development of Peptide Biopharmaceuticals in Russia Pharmaceutics. 2022
- International Standard: Prohibited List 2026 World Anti-Doping Agency. 2026