Free tool

Peptide half-life calculator

Educational pharmacokinetic math for estimating how much of a peptide remains after a given time period, based on its half-life. Select a common peptide from the dropdown to auto-fill the half-life, or enter a custom value. The tool does not suggest doses, routes, or administration schedules.

Select a peptide (optional) Initial amount

Half-life (hours) Time elapsed (hours)

🔒 Enter values and click Calculate to see results

This calculator stores nothing on this server. Email is captured by our delivery partner (Formspree) so we can send you the result and related research tools. No medication, health-condition, dosing, or current-use data is collected.

What this tool does

Calculates the remaining amount of a peptide after a given time, using first-order elimination kinetics: remaining = initial × 0.5^(elapsed ÷ halfLife).
Shows the remaining amount in both absolute units and as a percentage of the initial amount.
Provides a dropdown of common peptides with approximate half-life values drawn from FDA labels, peer-reviewed PK studies, and published clinical data.
Allows manual entry of any half-life value for peptides not listed in the dropdown.

What this tool does not do

No dosing recommendations or frequency suggestions.
No route or administration guidance.
No accounting for multi-compartment pharmacokinetics, nonlinear clearance, or dose-dependent half-life.
No personalized medical interpretation. Half-lives vary by formulation, route, metabolism, and individual.

Half-life values are from the Peptide Half-Life Reference Table. Many research peptides lack formal human pharmacokinetic data — see the reference for source quality and evidence gaps.

Free report

Want the full half-life reference table?

Get our source-backed pharmacokinetic reference for 32 peptides and peptide-related compounds, organized by category with FDA labels and peer-reviewed study citations.

V1 collects email, role, and topic interest only. No medication, health-condition, dosing, or current-use data is collected in this form.