Direct comparison of Semax and Selank — the two most studied Russian nootropic peptides. Compare BDNF vs GABAergic mechanisms, use cases, dosing, and which to choose for focus, memory, or anxiety.
ACTH analog that upregulates BDNF (brain-derived neurotrophic factor), enhances dopamine and serotonin transmission, and stimulates melanocortin receptor activity — driving focus, memory consolidation, and neuroprotection.
Synthetic tuftsin analog that modulates GABAergic activity, normalizes brain serotonin levels, and reduces the release of enkephalins — producing anxiolysis, mental clarity, and stress resilience without sedation.
Side-by-Side Comparison
| Property | Semax | Selank |
|---|---|---|
| Category | Cognitive | Cognitive |
| Mechanism | ACTH analog that upregulates BDNF (brain-derived neurotrophic factor), enhances dopamine and serotonin transmission, and stimulates melanocortin receptor activity — driving focus, memory consolidation, and neuroprotection. | Synthetic tuftsin analog that modulates GABAergic activity, normalizes brain serotonin levels, and reduces the release of enkephalins — producing anxiolysis, mental clarity, and stress resilience without sedation. |
| Half-Life | ~20 minutes (intranasal) | ~15–20 minutes (intranasal) |
| Typical Dosage | 100–300 mcg intranasal, 1–2× daily | 250–500 mcg intranasal, 1–2× daily |
| Primary Use | Cognitive enhancement, focus, memory, BDNF elevation, neuroprotection | Anxiety reduction, calm focus, stress resilience, cognitive clarity under pressure |
| Onset | Acute effects within 30–60 minutes; cumulative BDNF effects over 2–4 weeks | Anxiolytic effects typically within one dose; full effects build over 1–2 weeks |
| Stacks Well With | Selank, BPC-157, GHK-Cu | Semax, BPC-157, Epithalon |
Overview
ACTH analog that upregulates BDNF (brain-derived neurotrophic factor), enhances dopamine and serotonin transmission, and stimulates melanocortin receptor activity — driving focus, memory consolidation, and neuroprotection.
Synthetic tuftsin analog that modulates GABAergic activity, normalizes brain serotonin levels, and reduces the release of enkephalins — producing anxiolysis, mental clarity, and stress resilience without sedation.
Applications & Benefits
- Strong BDNF upregulation — the strongest nootropic mechanism studied
- Acute focus and motivation effects within one dose
- Neuroprotective in ischemia and oxidative stress models
- Enhances memory consolidation in multiple study models
- Stimulating without the cortisol burden of stimulant nootropics
- Anxiolysis without sedation — unique in the nootropic space
- Normalizes anxiety-driven cognitive impairment
- Anti-inflammatory neurological effects
- Excellent tolerability profile with minimal side effects
- Enhances immune function through tuftsin pathway
Semax vs Selank: Bottom Line
Semax and Selank address completely different aspects of cognitive performance. Semax drives active cognitive enhancement — BDNF elevation, focus, motivation, and memory — through stimulating dopaminergic and serotonergic pathways. Selank restores cognitive performance disrupted by anxiety and stress, through GABAergic modulation without sedation. The right choice depends on your primary bottleneck: if stress and anxiety are limiting your performance, Selank is the tool. If you need raw focus, memory support, and neuroplasticity enhancement, Semax is the stronger compound. Many protocols stack both — Semax for morning cognitive activation, Selank for evening stress regulation.
Compare Other Peptides
Mix and match any of the 19 peptides in our catalog for a custom side-by-side comparison.
Build New Comparison