Head to head
Selank and Semax are often marketed side by side as a matched pair from the same research tradition. They were studied for different primary purposes, and conflating them obscures what each compound's citations actually support.
Selank is a synthetic heptapeptide analog of tuftsin, studied in Russia primarily as an anxiolytic; an older comparative clinical study reported anxiolytic effects similar to a benzodiazepine comparator. Semax is a synthetic analog of an ACTH(4-10) fragment, studied in Russia for neuroprotective and nootropic properties, with much of the reviewed evidence coming from rat brain neuron research.
Both compounds draw heavily on a specific body of Russian-language pharmacology literature that has not been widely replicated in Western randomized trials. Selank's clinical comparator study is closer to a human trial than most of Semax's rat-level evidence, but neither has the kind of large, independent replication that would settle their effects definitively.
Because both are marketed as "cognitive" or "nootropic" peptides online, Selank's anxiety-focused evidence gets folded into general focus claims it was not designed to test. Semax's neuroprotective animal data gets similarly stretched toward everyday cognitive enhancement.
Read the full guides
Neurologic research
Selank is a synthetic peptide analogue of tuftsin, an endogenous immunomodulatory tetrapeptide, extended with additional amino acids; it is not the same molecule as tuftsin itself, and findings for one should not be assumed to apply directly to the other.
Read the research →Neurologic research
Semax is a synthetic peptide built on the ACTH(4-10) sequence with added amino acids (sometimes described as ACTH(4-7)PGP), distinct from natural ACTH itself and from related synthetic analogues such as ACTH(6-9)PGP studied in the same research programs.
Read the research →Reign Peptide · Business disclosure
Jorge Abreu is involved in Reign Peptide. Links to Reign are a business connection, not an independent endorsement. Reign lists these products for laboratory research, not human consumption.
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