Selank Half-Life Calculator
Selank is a synthetic analogue of tuftsin, an immunomodulatory peptide fragment, developed in the same Russian research tradition as Semax and registered there. Its half-life is a matter of minutes.
Half-life 5 min · peaks at 30 min
Every 24 hours.
Half-life
Left at next dose
Selank · once daily · levels plateau after ~25 min
Steady-state peak
1 mg
Steady-state trough
0 mg
Accumulation
None
At once daily, each dose has essentially cleared before the next one — levels don't accumulate, they repeat the same rise and fall. Clearance after a dose takes about 25 min.
This is a modelled estimate of relative levels from published half-life and time-to-peak figures — not a measured blood concentration. Individual pharmacokinetics vary.
Based on a published Selank half-life of about 5 min. The chart models RELATIVE levels from a unit dose — enter your own figures to see the shape. It is not a dose recommendation.
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What a 5 min half-life means in practice
A half-life of 5 min against once daily dosing means each dose has essentially cleared before the next arrives. That shapes the curve in three ways:
1. One half-life
Half the dose is gone after 5 min. After two half-lives 25% remains, after three 12.5%.
2. What's left at the next dose
Dosing once daily means the next dose lands 24 hours later, with about 0% of the previous one still present.
3. Accumulation and plateau
Almost nothing carries over, so levels don't accumulate — each dose repeats the same rise and fall, clearing in about 25 min.
Worked example
Selank has a half-life of 5 min. Dosing once daily, the next dose arrives 24 hours later with about 0% of the previous one still on board. That's little enough that levels don't build up: each dose rises and falls on its own, clearing in about 25 min.
A tuftsin analogue, registered in one jurisdiction
Selank is based on tuftsin — a four-amino-acid fragment of an immunoglobulin with immunomodulatory activity — extended with the same Pro-Gly-Pro tail used in Semax to slow degradation. It is registered as a medicine in Russia for anxiety-related indications and has no approval in the United States or the European Union.
Its published research is largely from the same institutional tradition as Semax and shares the same limitation: limited independent replication outside it. The half-life is very short, so as with Semax the practical questions concern route and onset rather than accumulation.
Frequently asked questions
This calculator is provided for informational and educational purposes only and is not medical advice. Always confirm dosing with a qualified healthcare professional and double-check your own measurements before administering anything.
Built by the Pep AI team.