Peptide Half-Life Calculator
Peptide Half-Life Calculator
Estimate remaining compound and the decay curve after injection.
Inputs
Decay timeline
Half-life checkpoints
| Time | Remaining (mcg) | % Remaining |
|---|
Frequently Asked Questions
Q1What is peptide half-life and why does it matter for dosing?
Half-life is the time required for the concentration of a compound to decrease by 50% in the body. It determines how frequently a compound must be administered to maintain stable levels. Short half-life compounds (minutes to hours) require frequent dosing; long half-life compounds (days) may only need weekly administration.
Q2How many half-lives until a peptide is fully cleared from the body?
After 5 half-lives, approximately 97% of a compound is eliminated. After 7 half-lives, over 99% is cleared. This is the standard used to determine when a compound is considered pharmacologically inactive for research washout periods.
Q3How do I calculate how much peptide remains after a certain time?
Use the formula: Remaining = Initial Amount × (0.5)^(time elapsed ÷ half-life). The Half-Life Calculator above automates this—enter your starting dose, the compound's half-life, and the elapsed time to see exactly how much remains.
Q4Does the administration route affect peptide half-life?
Yes. Subcutaneous injection produces longer effective half-lives than intravenous administration because the compound is absorbed slowly from the injection depot. Oral administration drastically shortens half-life for most peptides due to enzymatic degradation in the GI tract.