⚕️ Medical Disclaimer
⚕️ Medical Disclaimer: This article is for educational and informational purposes only. It does not constitute medical advice. Consult a qualified healthcare provider before using any peptide.
What Are Selank and Semax?
Selank and Semax are synthetic peptide nootropics developed at the Institute of Molecular Genetics, Russian Academy of Sciences. Selank (TP-7, Thr-Lys-Pro-Arg-Pro-Gly-Pro) is an anxiolytic heptapeptide analog of tuftsin that modulates GABA-A receptor gene expression and enhances BDNF production. Semax (Met-Glu-His-Phe-Pro-Gly-Pro) is a synthetic ACTH(4-10) analog that boosts BDNF and NGF production without hormonal side effects (Eremin et al., 2004, PMID: 15559753).
Last updated: March 2026
Both are approved pharmaceuticals in Russia and available as intranasal sprays. They work through complementary mechanisms — Selank reduces anxiety via GABA modulation while Semax enhances cognitive performance via neurotrophin upregulation — making them a popular nootropic stack.
Selank + Semax Dosing Protocol
Selank: 250-500 mcg intranasally (1-2 sprays per nostril), 2-3× daily. Course: 14-21 days, then 1-2 week break. Semax: 200-600 mcg intranasally, 2-3× daily. The 0.1% nasal spray delivers ~50 mcg per drop. Start low and titrate up. Can be used together or separately depending on goals (anxiety vs focus).
For SubQ reconstitution: Selank 5 mg vial + 2 mL BAC water = 2,500 mcg/mL. For 500 mcg: 20 units. Use the Reconstitution Calculator. Both peptides clear rapidly (half-life ~3-5 minutes), so effects come from downstream gene expression changes, not sustained receptor occupancy. See the Half-Life Visualizer.
How Do Selank and Semax Work in the Brain?
Selank modulates GABA-A receptor subunit gene expression — specifically upregulating the α2, β1, and ε subunits while downregulating the δ subunit. This shifts GABA-A receptor composition toward a profile associated with reduced anxiety without sedation. Unlike benzodiazepines, Selank does not directly bind GABA-A receptors, so there is no dependency, tolerance, or withdrawal risk (Zozulya et al., 2001, PMID: 11700032).
Semax upregulates BDNF (Brain-Derived Neurotrophic Factor) and NGF (Nerve Growth Factor) in the hippocampus and prefrontal cortex — the brain regions responsible for memory formation and executive function. BDNF promotes synaptic plasticity (the biological basis of learning), while NGF supports cholinergic neuron survival (Agapova et al., 2008, PMID: 19140041).
Selank vs Semax: When to Use Each
| Feature | Selank | Semax |
|---|---|---|
| Primary Effect | Anxiolytic (anti-anxiety) | Nootropic (cognitive enhancement) |
| Mechanism | GABA gene expression modulation | BDNF/NGF upregulation |
| Best For | Social anxiety, GAD, stress | Focus, memory, learning |
| Stimulating? | No (calming) | Mildly (dopaminergic) |
| Half-Life | ~3 minutes | ~5 minutes |
| Dependency Risk | None | None |
| Russian Approval | ✅ (anxiolytic) | ✅ (nootropic, stroke recovery) |
Use Selank for anxiety and stress. Use Semax for cognitive enhancement. Stack both for comprehensive nootropic effect. For sleep, combine Selank with DSIP.
Frequently Asked Questions
Are Selank and Semax safe long-term? No dependency, tolerance, or serious adverse effects documented in decades of Russian clinical use. Both are considered very well-tolerated.
Can I use Selank/Semax with other peptides? Yes — they act through unique mechanisms and do not interact with BPC-157, ipamorelin, GLP-1, or other common peptides. See stacking 101.
How quickly do they work? Anxiolytic effects of Selank within 15-30 minutes. Cognitive effects of Semax build over 3-7 days of consistent use due to downstream BDNF/NGF expression changes.
Are they legal in the US? Not FDA-approved, not controlled substances. Available as research peptides or through compounding pharmacies.
Can Selank help with sleep? Selank alone is not a sleep peptide, but reducing anxiety can improve sleep onset. For direct sleep support, see DSIP or Epitalon.