LL-37 Half-Life Calculator
LL-37 is the active form of the only cathelicidin found in humans — part of the innate immune system rather than a designed drug. Its half-life is short, and this calculator charts the resulting curve.
Half-life 1 hour · peaks at 30 min
Every 24 hours.
Half-life
Left at next dose
LL-37 · once daily · levels plateau after ~5 hours
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 5 hours.
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 LL-37 half-life of about 1 hour. The chart models RELATIVE levels from a unit dose — enter your own figures to see the shape. It is not a dose recommendation.
Never do this math twice.
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What a 1 hour half-life means in practice
A half-life of 1 hour 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 1 hour. 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 5 hours.
Worked example
LL-37 has a half-life of 1 hour. 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 5 hours.
An endogenous antimicrobial peptide
LL-37 is produced in the body from a precursor protein and forms part of innate immune defence. Unlike most compounds in this catalogue it is not a designed analogue of anything — it is a naturally occurring human peptide, studied in that capacity.
Its published literature covers direct antimicrobial activity and roles in immune signalling and wound repair, largely in laboratory and animal models. Being endogenous is sometimes read as implying safety when administered exogenously; it does not, because concentration, location and timing all differ from physiological production. Its half-life is short and nothing accumulates at realistic intervals.
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.