# GLP-1 Half-Life Chart: How Long Semaglutide, Tirzepatide and Others Stay in Your Body > Semaglutide (Ozempic, Wegovy, Rybelsus) has a half-life of about 1 week, and the Wegovy label says it stays in the circulation for about 5 to 7 weeks after the last dose. Tirzepatide (Mounjaro, Zepbound) has a half-life of about 5 to 6 days, so it takes roughly 4 weeks to clear by the usual five-half-life rule. Daily drugs such as liraglutide and orforglipron clear much faster. - URL: https://glpcalendar.app/blog/glp-1-half-life - Published: 2026-09-29 - Updated: 2026-09-29 - Publisher: GLP Calendar (https://glpcalendar.app) A drug's half-life is the time it takes for the amount in your blood to fall by half. It explains why semaglutide and tirzepatide are weekly shots, why a late dose can still count, and why these medicines linger for weeks after the last dose. Every value below comes from a US label or a published trial. ## What is the half-life of semaglutide, tirzepatide and other GLP-1s? Weekly GLP-1s have long half-lives: about 1 week for semaglutide and about 5 days for tirzepatide and dulaglutide. Daily and twice-daily drugs are much shorter: about 13 hours for liraglutide, 29 to 49 hours for orforglipron (Foundayo) and 2.4 hours for exenatide. The chart lists each value with time to peak and steady state. | Medication | Half-life | Peak after a dose | Steady state | Mostly cleared after | |---|---|---|---|---| | Semaglutide injection (Ozempic, Wegovy) | About 1 week | 1–3 days | 4–5 weeks | About 5–7 weeks | | Semaglutide tablets (Rybelsus, Ozempic and Wegovy tablets) | About 1 week | About 1 hour | 4–5 weeks | About 5–7 weeks | | Tirzepatide (Mounjaro, Zepbound) | About 5–6 days | 24 hours (range 8–72) | 4 weeks | About 4 weeks (est.) | | Dulaglutide (Trulicity) | About 5 days | 48 hours (range 24–72) | 2–4 weeks | About 4 weeks (est.) | | Orforglipron (Foundayo) | 29–49 hours | 4–8 hours | About 1 week | About 6–10 days (est.) | | Liraglutide (Victoza, Saxenda) | About 13 hours | 8–12 hours | Not stated | About 3 days (est.) | | Exenatide (generic twice-daily pen) | 2.4 hours | 2.1 hours | Not stated | Measurable for about 10 hours | | Retatrutide (investigational) | About 6 days | Not established | Not established | Not established | All values come from the US labels except retatrutide, which is not approved anywhere; its half-life comes from a 12-week phase 1b trial in people with type 2 diabetes. "(est.)" marks our estimate using the five-half-life rule explained below, because those labels give no washout figure. The semaglutide washout times are label statements: about 5 weeks (Ozempic, Rybelsus) and about 5 to 7 weeks after Wegovy 2.4 mg, 7.2 mg or the 25 mg tablet. ## What does half-life mean in plain terms? Half-life is how long it takes for the level of a drug in your blood to drop by half. After one half-life about 50% is left, after two 25%, and after five only about 3%. That is the basis of the common rule of thumb that a drug is essentially gone after about five half-lives. - After 1 half-life: 50% remains - After 2: 25% - After 3: about 12% - After 4: about 6% - After 5: about 3% The semaglutide labels fit this rule: a 1-week half-life, and a drug that stays in the circulation for about 5 to 7 weeks. The same math works in reverse. With regular dosing, levels build until the amount taken in balances the amount cleared, which takes roughly four to five half-lives. That matches the labels: steady state after about 4 to 5 weeks of weekly semaglutide and 4 weeks of tirzepatide. Both molecules last long because they bind to albumin, a blood protein; the tirzepatide label credits a fatty-acid chain that "enables albumin binding and prolongs the half-life." ## How long does Ozempic (semaglutide) stay in your system? About 5 to 7 weeks after the last dose, according to the US labels. The Ozempic label says semaglutide is present in the circulation for about 5 weeks after the last dose, and the Wegovy label says about 5 to 7 weeks after the last 2.4 mg or 7.2 mg injection or 25 mg tablet. Levels peak **1 to 3 days** after an injection. Semaglutide tablets peak about 1 hour after the dose but share the same 1-week half-life, because the molecule is the same. The labels also note that after an overdose, a long period of observation may be needed because of that half-life. "In your system" is not the same as "still working." The labels do not say how quickly appetite or other effects fade after stopping, and that likely varies from person to person. ## How long does Zepbound (tirzepatide) stay in your body? Roughly 4 weeks, as an estimate. The Zepbound label gives a half-life of about 5 to 6 days in people with obesity, and five half-lives is 25 to 30 days. The US label states no washout period; the EU label says to stop tirzepatide at least 1 month before a planned pregnancy because of its long half-life. Tirzepatide peaks a median of **24 hours** after an injection (range 8 to 72 hours) and reaches steady state after 4 weeks of weekly doses. Mounjaro and Zepbound contain the same molecule, so the same timing applies to both. ## What does half-life mean for a missed or late dose? Because weekly GLP-1s linger, the labels allow a late dose within a set window, but each label sets its own limit. The US Ozempic label allows a missed dose within 5 days, Zepbound within 4 days (96 hours), and Wegovy injection only if the next dose is more than 48 hours away. Check with your prescriber or pharmacist. Daily pills follow different rules. The Wegovy tablet label says to skip a missed tablet and take the next one the following day, while the Foundayo label says to take a missed dose as soon as possible without doubling up. Longer gaps matter because levels fall and stomach side effects can return on restart. The current Wegovy label says escalation should restart at a lower dose after 2 or more missed weekly doses in a row; the Foundayo label says the same after 7 or more missed daily doses. Full details are in our [missed-dose guide](https://glpcalendar.app/blog/missed-glp-1-dose), and what to expect on restart is in our [side effects timeline](https://glpcalendar.app/blog/glp-1-side-effects-timeline). ## What does half-life mean for pregnancy planning? The US semaglutide labels say to stop the medicine at least 2 months before a planned pregnancy, citing its long half-life or washout period. The US Zepbound and Foundayo labels say to stop when pregnancy is recognized and give no pre-conception washout; the EU tirzepatide label says at least 1 month before a planned pregnancy. The 2-month semaglutide window is a little longer than the 5 to 7 weeks the drug takes to clear. Tirzepatide can also make birth control pills less reliable: the US Zepbound label advises switching to a non-oral method, or adding a barrier method, for 4 weeks after starting and after each dose increase. The Foundayo label uses 30 days. Plan the timing with your prescriber before you start trying to conceive. ## What does half-life mean before surgery or anesthesia? GLP-1s slow stomach emptying, which the labels say may increase the chance of food getting into the lungs during anesthesia, and weekly drugs stay in the body for weeks. Advice on whether to pause them has changed since 2023, so the safest step is to tell your surgical and anesthesia team exactly what you take and when. How the guidance has shifted: 1. **June 2023:** the American Society of Anesthesiologists suggested considering holding weekly GLP-1s for a week before elective procedures, and daily ones on the day of the procedure. 2. **October 2024:** a joint statement from anesthesia, gastroenterology, bariatric surgery and endoscopic surgery societies said most patients can continue, based on shared decision-making. It named the dose-escalation phase, higher doses and stomach symptoms as higher-risk features, and allowed a liquid diet for at least 24 hours before the procedure when there is concern. 3. **January 2025:** a UK multidisciplinary consensus said patients should continue these drugs before surgery, with a full risk assessment. The US labels say available data are insufficient to recommend changes to fasting or pausing the drug, and ask patients to tell their providers before any planned procedure. Bring your current dose and the date of your last dose. A tracker such as GLP Calendar logs each shot or pill with its date, which makes this easy to report. ## What does half-life mean when switching GLP-1 medications? When you switch, the old medicine is still in your body for weeks, so labels build timing into the switches they cover. The Wegovy label starts tablets one week after the last 2.4 mg injection, and starts the injection the day after the last tablet. For switches between different molecules, US labels give no conversion; your prescriber decides. The Rybelsus and Ozempic tablets label also starts tablets one week after the last 0.5 mg Ozempic injection, and warns that Rybelsus and Ozempic tablets are not interchangeable milligram for milligram. In practice, the one-week gap falls where the next weekly injection would have been. ## How accurate are estimated GLP-1 level charts? Only roughly. Charts that show an "estimated medication level" are drawn from average values in labels and population studies, not from a blood test. Real levels vary widely between people, no effective level has been defined for weight management, and such a chart should never be used to change a dose or schedule. The Wegovy label shows how wide the spread is. At steady state, 90% of patients had average semaglutide concentrations between 27 and 186 nmol/L on the 25 mg tablet, versus 51 to 110 nmol/L on the 2.4 mg injection. Timing assumptions add more error: tirzepatide's peak can come anywhere from 8 to 72 hours after a shot, and tablet absorption depends on taking the pill on an empty stomach with no more than 4 ounces of water and waiting 30 minutes. A curve also cannot tell you whether the medicine is working. At most, it illustrates the general idea: levels build over the first weeks, rise and fall between weekly doses, and fade over weeks after stopping. Dose and timing decisions belong to the label and your prescriber. ## Bottom line - **Semaglutide:** half-life about 1 week; in the circulation for about 5 to 7 weeks after the last dose; US labels say stop at least 2 months before a planned pregnancy. - **Tirzepatide:** half-life about 5 to 6 days; roughly 4 weeks to clear by estimate; the EU label says stop at least 1 month before a planned pregnancy. - **Daily drugs** such as liraglutide and orforglipron clear in days. - Tell every surgical team what you take, follow each label's missed-dose window, and never use a level chart to make dosing decisions. For drug-by-drug details, see our guides to [semaglutide](https://glpcalendar.app/blog/semaglutide) and [tirzepatide](https://glpcalendar.app/blog/tirzepatide). ## Frequently asked questions ### Is semaglutide still in my body a week after my last shot? Yes. Its half-life is about 1 week, so a meaningful amount is still circulating 7 days after an injection. The Wegovy label says semaglutide remains in the circulation for about 5 to 7 weeks after the last dose. ### Why do the labels say to stop semaglutide 2 months before pregnancy? The US Wegovy label cites semaglutide's long half-life, and the Ozempic label cites its long washout period. Two months is a little longer than the 5 to 7 weeks the drug takes to clear, so plan the timing with your prescriber. ### Do GLP-1 pills leave the body faster than weekly shots? It depends on the molecule. Oral semaglutide (Rybelsus, Ozempic tablets, Wegovy tablets) has the same half-life of about 1 week as the injection, while orforglipron (Foundayo) has a half-life of about 29 to 49 hours and reaches steady state in about a week. ### Does a longer half-life mean more weight loss? No. Half-life mainly determines how often a medicine is taken and how long it lingers after the last dose. Weight loss depends on the molecule, the dose and the person, and trial results are averages that vary between individuals. ### Should I tell my surgeon when I took my last GLP-1 dose? Yes. The US labels ask patients to tell their healthcare providers before any planned surgery or procedure because these medicines slow stomach emptying. Your surgical and anesthesia team decides whether anything should change. ## Sources - [Wegovy (semaglutide) injection and tablets US prescribing information, rev. 06/2026, DailyMed](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=ee06186f-2aa3-4990-a760-757579d8f77b) - [Ozempic (semaglutide) injection US prescribing information, rev. 06/2026, DailyMed](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=adec4fd2-6858-4c99-91d4-531f5f2a2d79) - [Rybelsus and Ozempic tablets (oral semaglutide) US prescribing information, rev. 01/2026, DailyMed](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=27f15fac-7d98-4114-a2ec-92494a91da98) - [Zepbound (tirzepatide) US prescribing information, rev. 08/2026, DailyMed](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=487cd7e7-434c-4925-99fa-aa80b1cc776b) - [Mounjaro (tirzepatide) EU product information (SmPC), European Medicines Agency](https://www.ema.europa.eu/en/documents/product-information/mounjaro-epar-product-information_en.pdf) - [Foundayo (orforglipron) US prescribing information, rev. 07/2026, DailyMed](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=8ac446c5-feba-474f-a103-23facb9b5c62) - [Victoza (liraglutide) US prescribing information, rev. 10/2025, DailyMed](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=5a9ef4ea-c76a-4d34-a604-27c5b505f5a4) - [Trulicity (dulaglutide) US prescribing information, rev. 06/2026, DailyMed](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=463050bd-2b1c-40f5-b3c3-0a04bb433309) - [Exenatide injection (Amneal, generic) US prescribing information, rev. 05/2026, DailyMed](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=e6cb5c8f-e97f-4a6a-95a4-939fd2393949) - [Urva et al. Retatrutide (LY3437943) phase 1b trial in type 2 diabetes, The Lancet, 2022](https://pubmed.ncbi.nlm.nih.gov/36354040/) - [Kindel et al. Multi-society clinical practice guidance on GLP-1 receptor agonists in the perioperative period (ASA, AGA, ASMBS, ISPCOP, SAGES), Surgical Endoscopy, 2024](https://pmc.ncbi.nlm.nih.gov/articles/PMC11666732/) - [El-Boghdadly et al. UK multidisciplinary consensus on peri-operative management of GLP-1 and GIP agonists, Anaesthesia, 2025](https://pubmed.ncbi.nlm.nih.gov/39781571/) --- Educational content, not medical advice. GLP Calendar is a tracking app; it does not recommend or calculate doses.