Comparison Guide
Semax vs Selank: Cognitive & Neuroprotective Peptide Comparison
Semax and Selank are the two most widely studied nootropic peptides, both approved pharmaceuticals in Russia. While both support cognitive function, they work through fundamentally different neurotransmitter systems.
Bottom line: Semax is an ACTH(4-10) analog that enhances BDNF expression and modulates serotonin/dopamine pathways — primarily cognitive and neuroprotective. Selank is a tuftsin analog that modulates GABA-A receptors — primarily anxiolytic without sedation. Semax is better for focus, memory, and neuroplasticity. Selank is better for anxiety reduction and stress resilience. Both are administered intranasally and are commonly combined for complementary cognitive optimization.
Head-to-Head Comparison
| Property | Semax | Selank |
|---|---|---|
| Origin | ACTH(4-10) fragment analog | Tuftsin analog (immune peptide) |
| CAS Number | 80714-61-0 | 129954-34-3 |
| Size | 7 amino acids | 7 amino acids |
| Primary Target | BDNF / TrkB pathway | GABA-A receptor modulation |
| Neurotransmitters | ↑ BDNF, ↑ Serotonin, ↑ Dopamine | ↑ GABA, modulates Serotonin |
| Primary Effect | Cognitive enhancement, neuroprotection | Anxiolysis without sedation |
| Administration | Intranasal (nasal spray) | Intranasal (nasal spray) |
| Half-Life | ~3–5 minutes (rapid CNS uptake) | ~3–5 minutes (rapid CNS uptake) |
| Duration of Effect | 4–6 hours | 4–8 hours |
| Drug Approval | Approved in Russia (1994) | Approved in Russia (2009) |
| Sedation | None (stimulatory) | None (anxiolytic without sedation) |
| Best For | Focus, memory, neuroplasticity | Anxiety, stress, calm focus |
Semax: The Cognitive Enhancer
Semax is a synthetic analog of the ACTH(4-10) fragment, developed at the Institute of Molecular Genetics of the Russian Academy of Sciences. It has been an approved pharmaceutical in Russia since 1994 for cognitive disorders, stroke recovery, and optic nerve conditions.
Mechanism of Action
Semax's primary mechanism is the upregulation of Brain-Derived Neurotrophic Factor (BDNF) — the key protein responsible for neuroplasticity, learning, and long-term memory formation. It also modulates serotonin and dopamine metabolism, enhancing attention, motivation, and mood. The enhanced variant N-Acetyl Semax Amidate (NASA) adds acetyl and amide groups for improved blood-brain barrier penetration and extended duration.
→ View Semax productsSelank: The Anxiolytic Neuropeptide
Selank is a synthetic analog of the naturally occurring immune peptide tuftsin, developed at the same Russian institute as Semax. Approved since 2009 in Russia as an anxiolytic and nootropic, it represents a unique approach — an immune-derived peptide that modulates brain function.
Mechanism of Action
Selank modulates GABA-A receptor activity — the same receptor family targeted by benzodiazepines — but without the sedation, tolerance, or withdrawal risks. It enhances inhibitory neurotransmission to reduce anxiety while preserving cognitive clarity. Additionally, it influences enkephalin metabolism and stabilizes serotonin pathways.
→ View Selank product🧠 Combining Semax + Selank
The Semax + Selank combination is one of the most popular cognitive peptide stacks because the mechanisms are complementary:
Semax Contributes:
- • BDNF upregulation for neuroplasticity
- • Enhanced dopamine for motivation/drive
- • Neuroprotective signaling
- • Improved learning and memory encoding
Selank Contributes:
- • GABA-A anxiolysis without sedation
- • Reduced stress-induced cognitive impairment
- • Stabilized serotonin for mood balance
- • Immune modulation (tuftsin-derived)
Together, Semax provides the cognitive "accelerator" while Selank removes the anxiety "brake" — enabling clear, focused cognition without overstimulation.
