Selank: a non-benzodiazepine anxiolytic peptide, lightly tested

Selank is the anxiety-focused sibling to Semax: another Russian heptapeptide with a credible mechanism, a handful of human studies, and the same large caveat about where and how those studies were done. Its pitch — benzodiazepine-like calm without benzodiazepine baggage — is genuinely interesting, and genuinely under-proven.

What it is

Selank is a synthetic heptapeptide (sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro), built as an analog of tuftsin, an endogenous immunomodulatory peptide.^[1] It was developed in Russia (the Institute of Molecular Genetics and the Zakusov Research Institute of Pharmacology) as a peptide anxiolytic and is given intranasally. You’ll sometimes see it called “TP-7” — that’s a synonym, not a separate compound.

The mechanism: GABA, but not a benzodiazepine

Selank’s most interesting feature is how it calms. Rather than binding the benzodiazepine site, it appears to act as a positive allosteric modulator of the GABA system — nudging the brain’s main inhibitory signal.^[2] It also inhibits the breakdown of enkephalins (the body’s own opioid-like peptides), with a measured potency (IC50 ~15 µM) greater than standard peptidase inhibitors — a proposed route to its anti-anxiety effect.^[3] It additionally touches BDNF, serotonin metabolism and immune signaling in animal work. The practical implication of not being a benzodiazepine is the safety claim below: no benzodiazepine receptor agonism, in theory, means none of the sedation and dependence that define that drug class.

The human studies — small, but head-to-head with benzodiazepines

Unusually for a research peptide, Selank has been compared directly against benzodiazepines in anxious patients — which is the most useful thing about its human data, and also where its limits show.

Safety — promising profile, one flag

The recurring safety claim is that Selank delivers anxiety relief without the sedation, memory impairment, or dependence of benzodiazepines — and in the add-on trial it actually reduced phenazepam’s side effects.^[5] That is consistent with its non-benzodiazepine mechanism, but it rests on the same small, uncontrolled trials, so it should be read as preliminary. One additional preclinical signal worth flagging: in a lab study, Selank showed notable anticoagulant (anti-clotting) activity among related peptides — a theoretical bleeding consideration that has not been characterized in humans. There is no large human safety database for this compound.

Approval status

Selank is reported to have completed Phase III clinical testing in Russia as a selective anxiolytic and is treated as a marketed peptide drug there.^[1] It is not FDA-approved; in the United States it is available only as an unapproved “research peptide” or supplement, outside the framework that governs actual anxiety medications.^[4]

The honest bottom line

Selank is one of the more intriguing anxiolytic ideas in the peptide space: a GABA-modulating, non-benzodiazepine peptide that, in small Russian trials, matched benzodiazepines on anxiety while causing fewer side effects.^[2] That is a real, mechanistically coherent signal — but it is built on small, single-country, non-randomized studies, with no large Western RCT, thin safety data, and no FDA approval. Treat it as a promising but under-tested anxiolytic, not a proven benzodiazepine replacement — and note that what’s sold in the U.S. is an unregulated product, not the trialed drug. Its cognitive-focused sibling is Semax.