Selank Half-Life: How Long It Stays in Your System

Selank half-life

Half-life: no published half-life found (PubMed search, 2 Oct 2026). A half-life depends on the route (under the skin, into a vein, by mouth or nasal spray), so we report it per route with the study it came from.

What half-life means

Half-life is the time it takes for the amount of a drug in the blood to fall by half. After one half-life, about 50% is left; after two, about 25%; after four to five, only a few percent remain.

• A long half-life lets a drug be dosed less often, for example once a week.
• A short half-life means levels rise and fall quickly, which is why some peptides are given daily or more often.
• Effects can outlast blood levels, so half-life alone does not tell you how long a drug works.

What it means for dosing frequency

Dosing intervals used in published studies of Selank:

• daily, intraperitoneal (Animal · rat; Bulletin of experimental biology and medicine 2019, PMID 31625062)
• daily, intranasal and intraperitoneal (Animal · mouse; Eksperimental'naia i klinicheskaia farmakologiia 2016, PMID 29787664)
• single injection after the 10th trial (Animal · rat; Eksperimental'naia i klinicheskaia farmakologiia 2010, PMID 20919548)
• repeated, 15 min before training sessions (Animal · rat; Neuroscience and behavioral physiology 2003, PMID 14552529)

Changing the interval changes how much drug builds up between doses, so it is not a free choice.

Drug tests and sport

Selank: This is not named on the 2026 list. The catch-all class S0 prohibits any drug with no approval anywhere for human use, so it would be banned if no health authority has approved it, but we have not verified that for this substance.

Anti-doping labs use tests built for specific substances. Whether a given test detects Selank, and for how long, is not reported in the anti-doping literature we checked (as of 2 Oct 2026).