How Long Do Zepbound, Wegovy and Ozempic Stay in Your System?

Weekly injections have half-lives measured in days, which is why they are dosed once a week. The daily pill Foundayo clears much faster.

Tirzepatide's half-life is about 5 to 6 days in people with overweight, obesity or sleep apnea, so after about 25 to 30 days roughly 3% of the last dose remains.1 The label does not state how many weeks tirzepatide stays in the body. The estimate comes from halving the level once per half-life:

The rows are arithmetic, not lab measurements. Tirzepatide reaches its peak in the blood a median of 24 hours after a dose.1 Our guide to how long Zepbound takes to work covers the other end of the timeline. The label uses the 5-day half-life when it tells doctors how long to watch someone after an overdose.1

The Mounjaro label gives the same drug a half-life of about 5 days.2 Both labels report that tirzepatide exposure rises in proportion to the dose.1,2 They give one half-life for all strengths, so a 2.5 mg dose and a 15 mg dose clear at the same proportional pace, with the larger dose starting from a higher level. Compounded tirzepatide has no FDA label, so no official figure exists for it. Our Mounjaro vs Zepbound comparison covers how the two brands differ.

Wegovy's label says semaglutide will be present in circulation for about 5 to 7 weeks after the last 2.4 mg or 7.2 mg injection or the last 25 mg tablet.3 Its half-life is about 1 week.3 After an injection, semaglutide peaks in the blood 1 to 3 days later.3 For how quickly it starts working, see how long Wegovy takes to work.

The Wegovy pill is taken daily, but it contains the same long-acting molecule. That is why the label's 5-to-7-week estimate covers the 25 mg tablet too.3 For lower doses such as 0.25 mg, the label gives no separate figure.

The Ozempic label says semaglutide will be present in circulation for about 5 weeks after the last dose.4 Its half-life is about 1 week, and it reaches steady levels after 4 to 5 weeks of weekly injections.4 Ozempic tablets, which share a label with Rybelsus, also contain semaglutide with a half-life of about 1 week.5

Foundayo, the daily GLP-1 pill, has a half-life of about 29 to 49 hours, much shorter than the weekly injections.6 It reaches steady levels after about 1 week of daily dosing.6 See Foundayo vs Zepbound for how the pill compares with a weekly shot, and our best oral GLP-1 programs for where it is prescribed.

The Wegovy and Ozempic labels say to stop semaglutide at least 2 months before a planned pregnancy because of its long half-life.3,4 For weight reduction, the Wegovy label says to discontinue it when pregnancy is recognized.3 The Ozempic label, written for type 2 diabetes, says to use it in pregnancy only if the potential benefit justifies the potential risk to the fetus.4 The Wegovy label also says breastfeeding is not recommended while taking Wegovy tablets.3

The Zepbound label does not give a washout period before a planned pregnancy. It advises stopping Zepbound when a pregnancy is recognized.1 It also says tirzepatide may make birth control pills less effective. People using them should switch to a non-oral method, or add a barrier method, for 4 weeks after starting and after each dose increase.1 Our guide to GLP-1s, pregnancy and breastfeeding covers this in depth.

The labels do not set a stop date before surgery; they tell patients to inform their doctors about any planned surgery or procedure.1,3 GLP-1 drugs slow stomach emptying, and there have been rare reports of food or liquid entering the lungs under general anesthesia or deep sedation.1 The Zepbound label says available data are not enough to know whether stopping the drug beforehand would reduce that risk.1

Guidance from the American Society of Anesthesiologists and four other societies, issued in 2024, says most patients can continue GLP-1 drugs before elective surgery.7 People at the highest risk of stomach side effects may follow a liquid diet for 24 hours before the procedure.7 Your surgical team decides, so tell them which GLP-1 you take and when you last took it.

The drug's effects fade with it, and weight tends to return. In the STEP 1 extension, people who stopped semaglutide 2.4 mg regained two-thirds of their lost weight within a year.8 If price is the reason for stopping, our Wegovy cost guide and Zepbound cost guide list lower-cost ways to stay on treatment.

How long does Mounjaro 2.5 mg stay in your system? The Mounjaro label gives one half-life, about 5 days, for every dose.2 By the halving arithmetic above, about 3% of a dose remains after roughly 25 days.

How long does 0.25 mg of Wegovy or Ozempic stay in your system? The labels give a half-life of about 1 week but no dose-specific washout for 0.25 mg.3,4 The Ozempic label's general figure is about 5 weeks.4

If I restart after a break, do I start over? The Wegovy label says that after 2 or more missed doses in a row, prescribers should restart the step-up at a lower dose.3 Foundayo's label says the same after 7 or more missed daily doses.6 Ask your prescriber before restarting; our missed dose tool shows each label's timing.

Does the drug leave faster at a lower dose? The labels report one half-life across doses, so the proportional pace is the same; a lower dose simply starts from a lower level.1,3

If you are switching drugs rather than stopping, Wegovy vs Zepbound compares the two most common choices, and our GLP-1 rankings compare prescribing programs. For safety topics, see the safety hub.

This article is for information only and is not medical advice. Do not stop, pause or restart a GLP-1 without talking to your prescriber, and always tell your surgical team which GLP-1 you take.