Russian-developed nootropic peptides. One calms you down, the other lights you up. Both go up your nose.
Bottom line: These are complements, not competitors. Selank brings the calm, Semax brings the clarity. Many users stack them — Semax in the morning for focus, Selank in the afternoon for stress management. If you have to pick one: anxiety dominant, go Selank. Cognitive performance dominant, go Semax. Both are nasal spray, both have decades of Russian clinical use, neither has FDA approval.
| Selank | Semax | |
|---|---|---|
| Category | Anxiolytic peptide (tuftsin analog) | Nootropic peptide (ACTH analog) |
| Mechanism | Modulates GABA and serotonin systems — calming without sedation, plus immune system support | Upregulates BDNF and dopamine — cognitive enhancement, focus, neuroprotection |
| Reported dose | 250–500 mcg/day nasal (100–150 mcg per spray, 1–2 sprays per nostril) | 200–600 mcg/day nasal (0.1% solution, 1–2 sprays per nostril) |
| Frequency | 1–3x daily nasal spray | 1–3x daily nasal spray |
| Weight loss (trials) | Not a weight loss peptide | Not a weight loss peptide |
| Top side effect | Mild nasal dryness or stinging, occasional fatigue at higher doses | Mild nasal irritation, occasional headache in first few days, potential overstimulation |
| Evidence tier | Tier 2 — approved in Russia for anxiety since the 1990s, no FDA approval | Tier 2 — approved in Russia/Ukraine for stroke recovery and cognitive disorders, no FDA approval |
| Common vial size | 0.15% nasal spray (3 ml), or 5 mg lyophilized vials | 0.1% or 1% nasal spray (3 ml), or 5 mg lyophilized vials |
| Approval status | Approved in Russia. Not FDA-approved. Moved to Category 1 (Feb 2026) | Approved in Russia/Ukraine. Not FDA-approved. Moved to Category 1 (Feb 2026) |
Selank is the pick if anxiety, chronic stress, or emotional regulation is the primary goal. It calms without sedating — you stay functional, not foggy. Also interesting for immune support. Think of it as the anti-anxiety nootropic.
Semax is for cognitive performance — focus, motivation, mental clarity, complex problem-solving. The BDNF and dopamine upregulation makes it closer to a traditional nootropic. Better for study sessions, deep work, or recovery from neurological events.
These are complements, not competitors. Selank brings the calm, Semax brings the clarity. Many users stack them — Semax in the morning for focus, Selank in the afternoon for stress management. If you have to pick one: anxiety dominant, go Selank. Cognitive performance dominant, go Semax. Both are nasal spray, both have decades of Russian clinical use, neither has FDA approval.
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vialprep research · Sources: PubMed, FDA, peer-reviewed trials · How we verify