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Peptide Half-Life Decay Calculator

Enter a half-life and elapsed time to estimate how much of a peptide remains.

For research & education only. This is a simplified exponential-decay estimate for education. It is not medical advice and does not model any individual's pharmacokinetics. Research use only.

Peptides clear from the body following exponential decay. Given a half-life, this tool estimates how much of a starting amount remains after any elapsed time.

The model

Remaining = starting amount × 0.5 (time ÷ half-life)

Each half-life removes half of what is left: after one half-life 50% remains, after two 25%, after three 12.5%, and so on. This is a single-compartment approximation — real pharmacokinetics can involve absorption and multiple decay phases — so treat it as an educational estimate, not a clinical model.

Half-lives elapsedRemaining
150%
225%
312.5%
46.25%
53.13%

Frequently Asked Questions

How many half-lives until a peptide is gone?
After about 5 half-lives roughly 97% has cleared (3.1% remains), which is commonly treated as effectively eliminated for estimation purposes.
Is this the same as clinical pharmacokinetics?
No. This is a single-compartment exponential-decay approximation. Real absorption and multi-phase elimination make actual curves more complex; use this only as an educational estimate.

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