Visualize how your peptide clears from the body — half-life, steady state, and accumulation for every injection schedule.
Half-Life
~6 days
Time for 50 % to be eliminated
Steady State
~25.9 days
≈ 4.3 half-lives
Accumulation
×1.80
Cmax at steady state ÷ Cmax first dose
Gone After
~42 days
after last dose
| Hour | % of peak |
|---|---|
| 0 | 100 |
| 109.2 | 59.1 |
| 209.3 | 118.5 |
| 318.5 | 70 |
| 418.6 | 110.5 |
| 518.7 | 161.4 |
| 627.9 | 95.4 |
| 728 | 135.3 |
| 837.2 | 80 |
| 937.3 | 112 |
| 1037.4 | 156 |
| 1146.6 | 92.2 |
| 1246.7 | 128.1 |
| 1355.9 | 75.7 |
| 1465.1 | 44.8 |
| 1574.3 | 26.5 |
| 1683.5 | 15.6 |
| 1792.7 | 9.3 |
| 1901.9 | 5.5 |
| 2011.1 | 3.2 |
| 2120.3 | 1.9 |
Source: Eli Lilly SURMOUNT clinical trial data. Research tool. Uses a simplified first-order elimination model and normalizes concentration to % of peak. Not a medical or dosing recommendation. Retatrutide: ~6 days.
Enter a peptide, dose, dosing interval, and number of doses. The calculator plots the concentration over time as a percentage of the first-dose peak, and reports three key pharmacokinetic metrics: half-life, steady state, and accumulation.
Peptides follow first-order elimination — a fixed percentage clears per unit time. The half-life is constant regardless of dose. After 7 half-lives, less than 1 % of the dose remains.
When dosing regularly, a peptide accumulates until the amount taken in per dosing interval matches the amount eliminated. This equilibrium is called steady state and is reached at about 4.3 half-lives, independent of dose.
Plasma concentrations in mg or ng per mL require a volume of distribution that is only partially published for research peptides. A percent-of-peak Y-axis keeps the analysis honest: the relative clearance and accumulation are mathematically rigorous, while absolute plasma levels are not implied.
Each peptide links to its dedicated half-life profile with steady-state and clearance analysis.
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