GLP-1 Clearance Calculator
Enter the date of your last injection to estimate how much medication is still in your system and when it clears. Built from the half-life figures in each drug's FDA prescribing information.
Week by week
| Week after last dose | Estimated remaining |
|---|
Call your provider instead of waiting this out if you have:
- Blood in your stool, or black/tarry stool
- Severe or persistent abdominal pain
- Vomiting, or an inability to keep fluids down
- No bowel movement for several days along with bloating and a distended abdomen
- Fever, or unexplained weight loss beyond what the medication accounts for
What this calculator does and doesn't tell you.
It estimates drug levels, not symptoms. Those are different things, and confusing them is the most common mistake I see. Some people feel normal well before the medication is gone. Others stay constipated after it has cleared entirely — usually because months of eating far less left them short on fiber and fluid, and that doesn't correct itself. If that's you, the answer isn't waiting longer. Read why you're still constipated after stopping Ozempic.
Half-life figures come from each medication's FDA prescribing information, listed in Sources below.
The estimate uses standard first-order elimination. Individual clearance varies with kidney and liver function, body weight, and how long you were on the drug.
It assumes you stopped rather than tapered. A taper shifts the curve.
Common Questions
How long does semaglutide stay in your system?
Semaglutide has a half-life of about one week. The FDA prescribing information for WEGOVY states that semaglutide is present in circulation for roughly 5 to 7 weeks after the last 2.4 mg dose.
How long does tirzepatide stay in your system?
Tirzepatide — sold as Mounjaro and Zepbound — has an elimination half-life of about 5 days. Plasma levels fall to negligible amounts roughly 25 to 30 days after the final dose — about four weeks. The semaglutide numbers do not transfer; these are different molecules with different clearance.
Why am I still constipated after stopping?
Two things usually overlap. The medication leaves slowly, so its gut-slowing effect lingers. And the eating pattern that came with reduced appetite — less food, less fiber, less fluid — doesn't reset on its own. The second one needs to be addressed directly. See what actually helps.
Does clearance mean my symptoms stop?
No. Drug clearance and symptom resolution are separate. Use the timeline to set expectations, not as a deadline for how you should feel.
Sources
- Semaglutide half-life and duration in circulation: WEGOVY (semaglutide) injection, FDA prescribing information, Clinical Pharmacology 12.3. FDA Drugs@FDA.
- Gastrointestinal adverse effects of GLP-1 receptor agonists and their management. Gorgojo-Martínez et al., J Clin Med 2022. PMID 36614945.
- Tirzepatide elimination half-life: ZEPBOUND and MOUNJARO (tirzepatide) FDA prescribing information, Clinical Pharmacology. FDA Drugs@FDA.
- Dulaglutide and liraglutide half-life: TRULICITY and SAXENDA/VICTOZA FDA prescribing information, Clinical Pharmacology. FDA Drugs@FDA.
Ozempic, Wegovy, Mounjaro, Zepbound, Trulicity, Saxenda, and Victoza are registered trademarks of their respective owners. Velisoma is not affiliated with, endorsed by, or sponsored by any of them. Drug names are used here only to identify the medications being discussed.
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