DSIP vs Selank

Both sit under cognitive and sleep, and they are asked about together because the question underneath — which peptide for rest — does not separate them on its own.

DSIP is an endogenous nonapeptide, first isolated from the cerebral venous blood of rabbits, and the research around it concerns sleep architecture and circadian signalling rather than sedation. That literature is old, largely preclinical, and considerably smaller than its circulation online suggests; much of what is written about DSIP elsewhere rests on a handful of mid-century studies.

Selank is not a sleep compound at all. It is a synthetic heptapeptide analogue of tuftsin, extended with a Pro-Gly-Pro sequence to slow enzymatic degradation, and the published work is anxiolytic and neurotropic in character — enkephalinase inhibition, GABAergic modulation, BDNF expression. Its research context is daytime state, not night-time architecture.

So the decision is which end of the twenty-four-hour cycle the question sits at. A protocol built around sleep staging and one built around daytime anxiety are not interchangeable, and neither compound becomes the other at a different dose or hour of administration.

Both ship lyophilised and are stored at 2–8 °C. Purity, vial sizes, price per milligram and current availability in the table above are read from the live catalogue at page load rather than typed here, so they move when the catalogue moves.

Both are supplied for laboratory research only. Neither is sold for human or veterinary use.