⚕️ 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](https://pubmed.ncbi.nlm.nih.gov/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](/en/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](/en/half-life).
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](https://pubmed.ncbi.nlm.nih.gov/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](https://pubmed.ncbi.nlm.nih.gov/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](/en/blog/dsip-sleep-peptide-dosing-guide).
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](/en/blog/peptide-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](/en/blog/dsip-sleep-peptide-dosing-guide) or [Epitalon](/en/blog/epitalon-longevity-peptides).