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Semax and Selank: what these Russian nootropic peptides are

Semax and Selank are two synthetic peptides developed in Russia that often appear under the "nootropic" label: Semax linked to attention and cognition, and Selank to anxiety-related states. Both share a common scientific origin (Russian institutes), a heptapeptide structure, and a body of evidence concentrated almost entirely in Russian-language literature. This guide explains what they are, what each is researched for, and how they differ, always at an educational level. It is not medical advice or a recommendation for use; outside Russia these peptides are not approved for human use and are handled as research material (RUO).

What Semax and Selank are

Both are synthetic heptapeptides (seven-amino-acid chains) created in the Soviet Union and Russia in the late twentieth century. Semax derives from an inactive fragment of adrenocorticotropic hormone, ACTH(4-10), to which a Pro-Gly-Pro extension is added that stabilizes it and removes its hormonal activity. Selank is a synthetic analog of tuftsin, a naturally occurring immunomodulatory peptide. Both were designed with intranasal administration in mind, and both appear in Russian literature with clinical uses approved there — something that is not the case in the EU, US, or UK.

What each is researched for

For Semax, research centers on its ability to upregulate brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) in the hippocampus and cortex, with interest in cognition and attention; in Russia it has been studied mainly in post-stroke rehabilitation. For Selank, the focus is its anxiolytic profile: proposed mechanisms include modulation of GABAergic and monoaminergic signaling and inhibition of enkephalin-degrading enzymes, plus an increase in BDNF described in rodents. A small Russian trial compared it with the benzodiazepine medazepam in generalized anxiety.

How they differ

The simple way to remember it: Semax is associated with cognitive activation and attention (the BDNF/NGF neurotrophic pathway), while Selank is associated with a calming or anxiolytic effect (GABAergic and enkephalin pathways). They are not interchangeable and do not act on the same targets. That is why Russian literature often describes them in different contexts — Semax tied more to cerebrovascular recovery and performance, Selank to anxiety and stress states — even though both share the increase in BDNF as a common point and the same laboratory origin.

Evidence and regulatory status

The evidence for both comes mainly from Russian studies, many of them small, open-label, or non-randomized, plus rodent pharmacology; outside Russia, independent replication is scarce and there are no large randomized trials in leading Western journals. As for status: in Russia/CIS both have approved uses under prescription (Semax on the List of Vital & Essential Drugs; Selank as a nasal spray). In the EU, US, and UK neither is approved by the EMA, FDA, or MHRA, and when offered there it is only as a research chemical (RUO), outside any medical oversight.

Frequently asked questions

What is Semax?

Semax is a synthetic Russian heptapeptide derived from a fragment of the hormone ACTH(4-10) and stabilized with Pro-Gly-Pro. Research — mostly Russian — links it to the upregulation of neurotrophins such as BDNF and NGF and to interest in cognition and attention. In Russia it has approved clinical uses; in the EU/US/UK it is not approved and is handled as research material (RUO). This information is educational, not medical advice.

What is Selank researched for?

Selank is a synthetic analog of tuftsin studied mainly for its anxiolytic profile. Proposed mechanisms, based on Russian pharmacology, include GABAergic and monoaminergic modulation and inhibition of enkephalin breakdown, plus an increase in BDNF in rodents. Human evidence is limited and comes from small Russian trials. It is not approved by the FDA/EMA/MHRA and is treated as RUO outside Russia. This is not medical advice.

How does Semax differ from Selank as a nootropic?

Broadly, research associates Semax with cognitive activation and attention via the neurotrophic pathway (BDNF/NGF), and Selank with a calming or anxiolytic effect via GABAergic and enkephalin pathways. They share a Russian origin, a heptapeptide structure, and the increase in BDNF, but act on different targets and are not interchangeable. The Master of Peptides course studies these mechanisms in detail and on a purely educational basis.

✓ Last reviewed · 2026-07-22