Tirzepatide half-life & how long it lasts
Tirzepatide has a half-life of about 5 days (120 hours), reaches peak concentration around 24 hours after a dose, and is practically cleared from the body about 25 days (600 hours) after the last dose. Median tmax is 8–72 hours after a subcutaneous dose; the label reports a half-life of about 5 days, which is what makes once-weekly dosing work.
The numbers
| Half-life | 5 days (120 hours) |
|---|---|
| Time to peak | 24 hours |
| Route | injection |
| Typical cadence | once weekly |
| Practically cleared | 25 days (600 hours) after the last dose (five half-lives, ~97% eliminated) |
| Steady state | after roughly 25 days (600 hours) of continuous once weekly dosing |
| Evidence | FDA label or published human PK |
What that means day to day
- Levels are never zero between doses. On a once weekly schedule with a 5 days (120 hours) half-life, each dose stacks on what is left of the last one until steady state.
- Peak is not injection day. Concentration keeps climbing for about 24 hours after the shot, so effects and side effects lag the dose.
- Stopping is gradual. After the last dose it takes about 25 days (600 hours) for the compound to be practically gone.
Sources
Track it instead of estimating it
Bo models this curve from your own logged doses, so you can see what is still in your system right now instead of doing the arithmetic. It also handles reconstitution math, dose reminders and injection-site rotation.
Compare every compound in one table →
Educational information only. Bo is a tracking app, not a medical device, and nothing here is medical advice, a dosing recommendation, or a substitute for your prescriber. Half-lives are population averages from the sources cited on each row; individual clearance varies with body weight, kidney and liver function, and other medication.