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Drug level & half-life plotter

Plot the predicted drug level over time for a dose and dosing interval you choose. One-compartment model, first-order elimination, multi-dose accumulation up to steady state.

A neutral, educational tool. It shows the predicted shape of drug-level accumulation for the values you enter, not real plasma levels and not a dosing recommendation. It doesn't replace medical advice.

Published half-life ≈ 6.875 days (165 h) · FDA label, Ozempic®

mg
days
doses
Predicted drug level over timeLine chart of the relative drug level over time. Steady-state peak (Cmax) ≈ 1.975 mg-equivalent, trough (Cmin) ≈ 0.975 mg-equivalent, accumulation factor ≈ 1.975×.0.551.111.66011.723.33546.758.370Steady-state peak (Cmax)Steady-state trough (Cmin)Daysmg-equivalent
Steady-state peak (Cmax)1.975 mg
Steady-state trough (Cmin)0.975 mg
Accumulation factor (R)1.975×

Dashed vertical lines mark each dose. The horizontal dashed lines show the steady-state peak and trough. Values are relative mg-equivalents — the chart shows the shape of accumulation, not real plasma concentrations.

Titration scheme

Apply a stepwise escalation scheme instead of a constant dose and watch how the predicted level builds up during dose escalation.

Half-life sources

  • Semaglutide ≈ 7 days (~165 h) — FDA label, Ozempic®.
  • Tirzepatide ≈ 5 days (~120 h) — FDA label, Mounjaro®.
  • Retatrutide ≈ 6 days (~144 h) — Jastreboff et al., NEJM 2023 (phase 2).

Simplified one-compartment model with first-order elimination and multi-dose superposition (k = ln2 / half-life, accumulation R = 1 / (1 − exp(−k·τ))). It ignores absorption, bioavailability and distribution volume and is a teaching tool, not a clinical predictor.

Half-lives reflect published studies and prescribing information. This is not medical advice and not a dosing recommendation.