Semax vs Selank: Cognitive vs Anxiolytic Peptide Comparison
Semax is a synthetic heptapeptide derived from ACTH(4-10) that enhances cognition, focus, and memory through BDNF upregulation and dopaminergic modulation. It is approved in Russia for stroke recovery and cognitive disorders. Selank is a synthetic heptapeptide derived from the immunopeptide tuftsin that provides anxiolytic and immunomodulatory effects through GABAergic enhancement and enkephalinase inhibition. Both were developed at the Russian Institute of Molecular Genetics, share intranasal administration, and feature the stabilizing Pro-Gly-Pro C-terminal extension, but target different neurological pathways.
Side-by-Side Comparison
| Parameter | Semax | Selank |
|---|---|---|
| Mechanism | BDNF upregulation; dopamine/serotonin modulation; neuroprotection | GABAergic enhancement; enkephalinase inhibition; cytokine regulation |
| Evidence Grade | B+ | B |
| Derived From | ACTH(4-10) + Pro-Gly-Pro | Tuftsin + Pro-Gly-Pro |
| Primary Effect | Cognitive enhancement, focus, neuroprotection | Anxiolytic, immune modulation, stress reduction |
| Route | Intranasal (primary); subcutaneous | Intranasal (primary); subcutaneous |
| Typical Dose | 200 - 600 mcg/day intranasal | 250 - 500 mcg/day intranasal |
| Half-Life | ~2-3 minutes (plasma); effects last hours | ~2-3 minutes (plasma); effects last hours |
| Best For | Focus, memory, stroke recovery, ADHD research | Anxiety, stress, immune support, GAD research |
| FDA Status | Not FDA-approved; approved in Russia | Not FDA-approved; approved in Russia |
| Cost (research grade) | $$ | $$ |
Semax: Pros & Cons
Advantages
- Potent BDNF upregulation (neuroprotective)
- Enhances focus, attention, and memory
- Approved in Russia for stroke and cognitive disorders
- Non-invasive intranasal administration
- No reported dependence or withdrawal
- Neuroprotective against ischemic damage
Considerations
- Most clinical data in Russian-language literature
- Very short plasma half-life (minutes)
- Not FDA-approved in Western countries
- May cause irritability in sensitive individuals
- Limited Western clinical trial data
Selank: Pros & Cons
Advantages
- Anxiolytic without sedation or dependence
- Dual anxiolytic + immunomodulatory effects
- Non-invasive intranasal delivery
- No benzodiazepine-like side effects
- Enhances enkephalin levels naturally
- Approved in Russia for anxiety disorders
Considerations
- Weaker cognitive enhancement than semax
- Most clinical data in Russian literature
- Not FDA-approved
- Short plasma half-life
- Limited availability outside research suppliers
- Less studied than benzodiazepines for anxiety
Which Is Right for Your Research?
Decision Guide
Choose semax if: Your research targets cognitive enhancement, focus improvement, BDNF-mediated neuroprotection, stroke recovery, or ADHD-related mechanisms. Semax's dopaminergic and BDNF-modulating properties make it the stronger nootropic for pure cognitive performance research.
Choose selank if: Your research targets anxiety reduction without sedation, stress resilience, immune modulation, or generalized anxiety disorder mechanisms. Selank's GABAergic and enkephalinase-inhibiting properties provide anxiolytic effects without the dependence or cognitive impairment associated with benzodiazepines.
Stack both if: Your research requires both cognitive enhancement and anxiety reduction. The semax + selank stack is the most popular nootropic peptide combination, with semax providing focus/BDNF upregulation and selank providing calm/anxiety reduction. A common protocol uses semax in the morning and selank in the afternoon.
Frequently Asked Questions
Semax is generally more effective for focus and cognitive enhancement. Its ACTH-derived mechanism upregulates BDNF and modulates dopamine/serotonin for attention and memory. Selank can indirectly improve focus by reducing anxiety, but its primary target is GABA-mediated anxiolysis.
Yes, they are commonly stacked as complementary nootropic peptides. Semax for focus/BDNF and selank for anxiety reduction/immune support. Both use intranasal delivery, making combined protocols practical. A typical approach uses semax in the morning and selank later in the day.
Semax derives from ACTH(4-10) targeting cognition through BDNF and dopaminergic pathways. Selank derives from tuftsin targeting anxiety through GABAergic enhancement and enkephalinase inhibition. Both were developed at the same Russian institute and share the Pro-Gly-Pro stability modification.
Related Protocol Guides
Compare More
Verified Research Suppliers
- ★ LiveWell Peptides — Official Sponsor • cGMP Certified Paid partnership
- Core Peptides — Third-party tested
- Limitless Life Nootropics — Broad catalog
- Biotech Peptides — USA-based
- Amino Asylum — Budget-friendly
© 2026 Path to Peptides™. For research and educational purposes only. Not medical advice.
Some links on this site may earn a commission at no cost to you.