← Full peptide calculator
FREE TOOL
Estimate how a peptide builds up and clears with repeated dosing. Enter a half-life — or load a published reference value where one exists — plus your dose and interval, and this free calculator shows the build-up to steady state, how much carries over between doses, the time to reach steady state, and the washout after your last dose. Arithmetic and estimate only — not medical advice.
One-compartment, first-order model: k = ln(2) ÷ half-life; accumulation = 1 ÷ (1 − e^(−k·interval)); steady state and washout ≈ 5 half-lives. Shows the estimated amount remaining in the body relative to one dose — not an absolute plasma concentration. Estimate and arithmetic only — not medical advice. Reference half-lives are approximate published figures; several research peptides have no established human half-life.
Frequently asked questions
What is a peptide’s half-life?
The half-life is the time it takes for the amount of a compound in the body to fall by half. A short half-life clears quickly; a long one lingers and builds up with repeated doses. This calculator uses it to estimate accumulation and washout — it does not measure your individual levels.
How long until a peptide reaches steady state?
As a rule of thumb, repeated dosing reaches steady state after roughly five half-lives — the point where the amount carried over between doses stops rising. Enter a half-life and interval and the tool estimates the time to steady state for you.
Why don’t all peptides have a preset half-life?
Because several research peptides — including BPC-157, TB-500 and GHK-Cu — have no well-established human half-life in the published literature. Rather than invent a number, the tool marks them as “not established” and asks you to enter your own value.
Is this medical advice?
No. It is a general pharmacokinetic estimate and arithmetic tool only. It shows relative amounts, not your actual blood levels, and it does not recommend a dose or schedule. Always verify with a clinician, the product label, or a pharmacist.