Semax vs Selank
Semax and Selank are both Russian-developed nootropic peptides administered intranasally, but they target different aspects of brain function. Semax is primarily discussed for cognitive enhancement and neuroprotection, while Selank is focused on anxiety reduction and stress resilience.
Semax and Selank are Russian-developed nasal-spray nootropics that look similar but do different jobs. Semax is the "focus and neuroprotection" one — it boosts BDNF and modulates dopamine/serotonin. Selank is the "calm" one — it's anxiolytic without sedation, working through GABA and serotonin metabolism. Most Western evidence is translated from Russian clinical literature, which limits the confidence of any recommendation.
Semax
A synthetic peptide analog of ACTH(4-10) developed in Russia, studied for cognitive enhancement and neuroprotection.
Selank
A synthetic peptide analog of tuftsin with anxiolytic and nootropic properties, developed in Russia.
| Category | Semax | Selank |
|---|---|---|
| Primary Focus | Cognition, focus, neuroprotection | Anxiety reduction, stress resilience, calm |
| Key Mechanism | BDNF upregulation, dopamine/serotonin modulation | GABA enhancement, serotonin metabolism modulation |
| Regulatory Status | Approved in Russia for cognitive/neurological conditions | Approved in Russia for generalized anxiety |
| Evidence Base | Moderate (primarily Russian clinical literature) | Moderate (primarily Russian clinical literature) |
| Typical User Profile | Seeking focus, mental clarity, cognitive support | Seeking calm, anxiety relief, stress management |
| Administration | Intranasal spray | Intranasal spray |
In depth
Same family, different jobs
Semax and Selank are both heptapeptides derived from fragments of larger endogenous proteins — Semax from ACTH, Selank from tuftsin — and both are delivered as intranasal sprays, which bypasses first-pass metabolism and gets the peptide reasonably close to the brain. But the pharmacology diverges from there. Semax's headline effect is upregulation of BDNF (brain-derived neurotrophic factor) along with modulation of dopamine and serotonin — the profile of a cognitive enhancer and neuroprotectant. Selank's headline effect is anxiolysis without sedation, apparently mediated by enhanced GABA signaling and modulation of serotonin metabolism — the profile of a calming agent that doesn't blunt function.
When Semax fits
Semax is the one you hear about for focus, mental clarity, and protection during cognitive stress. In Russia it's an approved therapy for cognitive disorders following stroke and traumatic brain injury — a meaningful neuroprotective signal, not just a "smart drug" gimmick. Off-label, it's used for sustained attention, recovery from cognitive burnout, and as an adjunct in post-concussion contexts. Reported effects tend to be subtle and cumulative rather than stimulant-like; users describe sharper thinking and more stable focus rather than caffeine-style alertness.
When Selank fits
Selank is the one you hear about for anxiety, stress resilience, and emotional regulation. It's approved in Russia for generalized anxiety disorder. The unusual claim for Selank is anxiolysis without the sedation, dependence, or cognitive-blunting profile of benzodiazepines — if it lives up to that description, it's genuinely useful. Reports tend to describe reduced baseline anxiety and better stress tolerance rather than a benzodiazepine-like acute calm.
The evidence caveat
Both compounds have moderate clinical evidence bases — but almost all of it is Russian-language clinical literature, much of it conducted decades ago, and Western clinical trials are essentially absent. That's not a reason to dismiss them, but it is a reason to calibrate expectations. The translated summaries that circulate online are often thin, and independent replication by Western neuroscience labs hasn't happened in a meaningful way.
Bottom line
If cognition and focus are the primary goal, Semax is the compound discussed. If anxiety and stress are primary, Selank is. Some users stack them — Semax for drive, Selank for balance — and the mechanisms don't obviously conflict. Both should be used under clinician guidance, both come with the Russian-evidence asterisk, and neither is FDA-approved in the US. The intranasal delivery is specific: oral and subcutaneous routes are not how the existing evidence was generated, and dose-response data outside the nasal route is sparse.
These peptides are often used together. See our stack profiles for combination details.