Semax & Selank: the nootropic peptides, explained

What they are

Semax is a synthetic heptapeptide — an analog of a fragment of ACTH (adrenocorticotropic hormone), specifically the ACTH(4–10) region, with a Pro-Gly-Pro tail added for metabolic stability. It's developed in Russia and classed as a nootropic / neuroprotective peptide. (Note: "N-Acetyl Semax" and "Semax amidate" are modified research-market variants; the registered-Semax science doesn't automatically transfer to them.)

Selank is a synthetic heptapeptide analog of the endogenous immunomodulatory peptide tuftsin, developed at the Institute of Molecular Genetics of the Russian Academy of Sciences, and classed as an anxiolytic (anti-anxiety) peptide.

Their shared distinctive trait: both are commonly used intranasally (nasal drops or spray) rather than injected — peptides have poor oral bioavailability, and the intranasal route is used to reach the central nervous system.

What the evidence actually shows

The honest version, because this is where pages overclaim. Both peptides are registered, used medicines in Russia — Semax for ischemic stroke and cognitive/ischemic conditions (it's on Russia's essential-drugs list), Selank for anxiety. The reported mechanisms are reasonably documented in rodents: Semax rapidly raises BDNF and modulates dopaminergic/serotonergic systems; Selank acts as a positive allosteric modulator of GABA signaling and slows enkephalin breakdown.

But the evidence base is dominated by Russian-language studies and animal models, with few high-quality, independent, blinded Western RCTs. So the honest reading: these are not unstudied compounds — there's real Russian clinical use and a coherent mechanistic story — but their efficacy is not Western-validated, and long-term safety data outside Russia is limited. Treat the cognition/anxiety claims as preliminary and region-specific, not as settled medicine.

Route & dosing

Both are short-acting peptides (rapid systemic degradation), which is part of why the intranasal route is favored — it delivers toward the CNS, and reported effects last hours despite the short plasma half-life. They're sold either as pre-mixed nasal sprays/drops or as lyophilized powder reconstituted with bacteriostatic water (then used intranasally or injected). Dosing is in micrograms; commonly reported figures are roughly 200–600 mcg/day for Semax and a broadly similar range for Selank.

These figures are what's commonly reported, not a recommendation — they come from product labels and community practice, not standardized Western clinical guidelines. If you're reconstituting a powder for a measured dose, the same arithmetic the peptide reconstitution calculator does applies (concentration = mg ÷ mL; dose volume = target ÷ concentration). And because this is research-grade material in the West, purity and content are not guaranteed.

Safety & the stack

In the available (mostly Russian/animal) studies both are reported generally well-tolerated — Selank is noted for anxiolytic effect without benzodiazepine-style sedation or dependence in those reports — but long-term and Western safety data are limited, and nasal irritation is a plausible local effect. The two are frequently run together as a "nootropic stack" (Semax for drive/focus, Selank for calm), on the theory they cover complementary axes — but that's community practice, not clinical guidance, and the combination isn't trial-validated.

Tracking Semax & Selank in OptiPin

If you're tracking a nootropic-peptide protocol, OptiPin treats each as its own entry — without endorsing it:

• Two compounds, separate logs — Semax and Selank each get their own schedule and dose log, even when run as a stack.
• Intranasal dosing + reminders — record each intranasal (or injected) dose and get reminded on schedule.
• Subjective tracking that resists placebo — log a structured focus/anxiety/mood rating over time so a trend lines up against dosing — the honest way to judge a subjective nootropic on yourself.
• OptiInsight analysis — OptiPin's AI reads the full record (doses, ratings, symptoms) and surfaces what moved with what.
• Supply tracking — log the bottle/vial; OptiPin estimates remaining doses and an empty date.