Semax and Selank are often lumped together as Russian “nootropic” peptides, but they target different problems — cognition and focus versus anxiety and stress.
Research reference only. Not medical advice, prescribing guidance, or a product recommendation.
| Dimension | Semax | Selank |
|---|---|---|
| Derived from | ACTH(4-10) | Tuftsin |
| Primary research focus | Cognition, focus, neuroprotection | Anxiety, stress resilience |
| Key mechanism | BDNF / trkB upregulation; dopaminergic & serotonergic tone | GABAergic & serotonergic modulation; enkephalinase inhibition |
| HPA (stress) axis | Not activated | Not activated |
| Sedation / dependence | No | No (unlike benzodiazepines) |
| Common form | Intranasal (research) | Intranasal (research) |
| Russian clinical status | Approved (stroke, cognition, optic nerve) | Approved (anxiety) |
| FDA approval | None | None |
Semax, an ACTH(4-10) analog, is studied for upregulating BDNF and trkB in the hippocampus and basal forebrain (Dolotov et al., 2006) and for enhancing dopaminergic and serotonergic signaling — without activating the stress axis. That profile underlies its association with attention, memory, and neuroprotection; it is approved in Russia for stroke, cognitive impairment, and optic-nerve disease.
Selank, derived from the immunopeptide tuftsin, is studied for anxiolytic effects via GABAergic and serotonergic modulation, with clinical reports of benzodiazepine-comparable anxiety relief but without sedation or dependence. The simplest model: Semax sharpens, Selank soothes — which is why the two are frequently studied as a complementary pair.
These are complements, not substitutes: Semax for cognition / neuroprotection, Selank for anxiety / calm. Both avoid the HPA-axis activation and dependence concerns of older agents in their respective spaces. The important caveat for both is evidence quality — most controlled data are Russian-language, and independent Western replication is limited. Neither is FDA-approved.
Semax is an ACTH(4-10) analog studied for cognition, focus and neuroprotection via BDNF upregulation. Selank is a tuftsin analog studied for anxiety via GABAergic and serotonergic modulation. A simple model: Semax to sharpen, Selank to soothe.
In the research literature they are often studied as a complementary pair — Semax for cognitive / neuroprotective endpoints and Selank for anxiety — because their mechanisms and targets differ.
Research interest in both centers on effects without the sedation, tolerance, or withdrawal associated with classic agents (e.g. benzodiazepines for Selank), and neither activates the HPA stress axis.
No. Both are approved and used in Russia but are research compounds elsewhere and not FDA-approved. Western peer-reviewed replication is limited. This page is a research and educational reference.