How much is in my system?
Estimate your semaglutide or tirzepatide level from your shot history: where it is today, when it peaks, and how long it takes to clear.
Estimated level (mg)
thatglp charts your medication level automatically from every shot you log, reminds you on shot day, and puts your next shot and current level right on your home screen.
Start my free trialHow the estimate works
Each shot is absorbed from under your skin over the first few days, then cleared at a steady rate. The estimate adds up what's left from every shot you've logged, using published averages:
Tirzepatide: half-life about 5 days, peak about 24 hours after a shot, about 80% absorbed.
Semaglutide: half-life about 7 days, peak about 2 to 3 days after a shot, about 89% absorbed.
Because each shot overlaps the ones before it, levels climb for the first 4 to 5 weeks on a new dose before settling into a steady weekly rise and fall.
Common questions
How long does Ozempic or Wegovy stay in your system?
Semaglutide halves about every 7 days. It takes about five half-lives, roughly 5 weeks after your last dose, to be mostly cleared.
How long does Mounjaro or Zepbound stay in your system?
Tirzepatide halves about every 5 days, so it's mostly cleared about 25 days after your last dose.
When does a shot peak?
Tirzepatide usually peaks 8 to 72 hours after an injection, and semaglutide 1 to 3 days after. Many people notice appetite and side effects follow a similar rhythm through the week.
I missed a dose. What should I do?
Each medication has its own missed-dose rule on its label, and compounded medication may come with different instructions. Check your label or ask your pharmacist or prescriber instead of using this chart to decide.
Does this work for oral semaglutide (Rybelsus) or daily injections?
No. This estimator is for weekly-style injections of semaglutide or tirzepatide.
When is your next dose increase? Plan it with the dose schedule planner →
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