Is Semax with selank and dihexa legal in the United States?

Three nootropic peptides sold as one cognitive stack. Two are registered medicines in Russia with small domestic trials; the third rests on a paper that was retracted in 2025 after an expression of concern in 2021. The combination has never been tested, and no vial size is standard across sellers.

The pitch is one activating peptide, one calming peptide and one synaptogenic peptide, covering focus, anxiety and long-term plasticity. Each third of that pitch has a different evidentiary problem.

Mechanism: Semax is described as modulating BDNF and trkB expression in rodent hippocampus and as having neuroprotective effects in the Russian clinical literature. Selank is a tuftsin analogue with anxiolytic activity linked to enkephalin metabolism.

Regulatory history: None of the three is approved in the United States. Semax and selank hold registrations in Russia; dihexa has never been approved anywhere and never completed clinical development.

Approves prescription drugs by indication and polices unapproved products, including peptides sold online. Compounding pharmacies may prepare some compounds under a prescription when the FDA places them on a permitted bulk-substances category.

The classification above is the The Longevity Archive reading of U.S. Food and Drug Administration listings for Semax with selank and dihexa at the reviewed date, not a legal opinion. Rules change, and importing, prescribing and possessing a compound can each be treated differently. Check the regulator directly before acting on anything here.