Semax / Selank

Two Russian-developed peptides in one vial: Semax, registered in Russia as nasal drops for stroke and cognitive problems, and Selank, registered there as nasal drops for anxiety. This is plain Semax, not the N-acetyl/amidate variant.

Both carry a stabilizing Pro-Gly-Pro tail and inhibit enkephalin-degrading enzymes in lab studies. Rat work points to effects on BDNF for Semax and on GABA-related genes for Selank.

Both have real clinical use abroad, but only as nasal drops, and all labeling and human studies are intranasal. There are no human data for either in other forms, and FDA's 2026 Semax review found no human pharmacokinetic data by any route. The two have been compared in animals, but no human study of the combination was found.

Nasal-drop safety (mild irritation, allergy) can't be assumed for other forms. Semax increased stimulant-driven dopamine release in mice and its Russian label excludes anxiety disorders and seizure history, while Selank is sold as an anti-anxiety product, so the pairing makes reactions hard to attribute. Semax's animal anticlotting effects and FDA's immunogenicity concerns for both are noted.

Neither is FDA-approved; both are approved in Russia as nasal drops. FDA advisers voted 8–5–1 in July 2026 to recommend adding Semax to the 503A bulks list, but the vote is advisory and no final rule had followed as of October 2026; Selank's nomination was withdrawn and never reviewed, so neither is compoundable. Neither is named on the 2026 WADA list.