How long will semaglutide stay in your system after your last dose?

You've just had your last dose — here's what happens next

Picture the day after your final Wegovy injection. The medicine doesn't switch off immediately; it fades in a predictable curve. Semaglutide's half-life is close to seven days, which is part of why a once-weekly injection works at all. Each week, roughly half the remaining concentration leaves your bloodstream. The NHS medicines information for semaglutide describes this prolonged activity as a property of the molecule itself — it binds to albumin in the blood, which slows the kidneys from clearing it quickly.

By week two, you're at about a quarter of peak levels. By week five, you're at roughly three percent of where you started. Most clinical pharmacologists treat five half-lives as the practical definition of a drug being cleared, which puts full elimination at around five weeks after stopping semaglutide. That's a useful rule of thumb, though body weight, kidney function and age all nudge the exact figure slightly. For surgical planning or pregnancy timing, the safest course is always to let your prescriber give you a specific date rather than relying on general estimates.

One thing that surprises people: the appetite-suppressing effect can linger a little after blood levels drop. That's not because the drug is still at therapeutic levels, it's partly because the gut and brain take time to recalibrate. You might eat less than usual for a week or two after stopping, even as the medicine fades. On the flip side, hunger during the first week of Wegovy is common precisely because levels haven't yet reached steady state.

Why the oral tablet's elimination timeline is slightly different

If you've been taking Wegovy tablets rather than the injection, the pharmacokinetics are broadly similar but not identical. Oral semaglutide reaches peak blood levels more quickly on a daily basis, but the same roughly seven-day half-life applies once you stop. The molecule is the same; the absorption route isn't. For questions about how long semaglutide lasts in your system specifically for the tablet form, the same five-week estimate applies as a general guide.

One practical difference with the tablet: because it must be taken on a completely empty stomach and absorption depends on timing, any missed or improperly timed doses affect both blood levels and the elimination window. If you've been inconsistent with timing, the five-week clock is best discussed with the prescriber who knows your actual history. The time it takes Wegovy to work is linked to reaching steady-state levels, and the same logic applies in reverse when you stop.

There's also an honest acknowledgement worth making here: if you're reading this because you're nervous about stopping semaglutide, or wondering whether you'll regain weight once it leaves your system, that's a completely reasonable thing to be thinking about. It's one of the questions our prescribers hear regularly. Weight regain after stopping GLP-1 medicines is real and documented in clinical trials; the conversation about if and how to stop is best had before the decision is made.

Specific situations where the timeline is clinically important

Surgery is the clearest case. NHS England's guidance on weight-management injections advises telling your anaesthetist and surgical team that you take a GLP-1 medicine before any procedure. Semaglutide slows gastric emptying, which raises aspiration risk under general anaesthesia even if you've fasted the standard number of hours. Your surgical team may ask you to stop a specific number of weeks ahead; they will want to know when your last dose was and factor in the half-life accordingly.

Pregnancy planning is another. Semaglutide is not recommended during pregnancy, breastfeeding, or while trying to conceive. Guidance advises stopping the medicine and allowing it to clear before attempting conception; the MHRA recommends using contraception throughout treatment. For tirzepatide users wondering about how Wegovy compares on this point, the clearance timelines differ because tirzepatide has a different half-life. A prescriber will give you the right figure for whichever medicine you take.

Finally, if you're switching from semaglutide to another medicine or vice versa, the overlap period matters. Starting a new GLP-1 agent before the previous one has cleared could compound side effects. This is not a decision to make based on general reading; it sits within the clinical review that comes with every consultation through a regulated service. The full Wegovy treatment overview covers what clinical assessment looks like at the start of treatment, which applies equally when stopping or switching.

What the research actually says about steady state and elimination

The STEP 1 trial, published in the New England Journal of Medicine, established semaglutide 2.4mg's clinical profile across 68 weeks and included pharmacokinetic data consistent with the seven-day half-life described above. Steady-state levels are typically reached after four to five weeks of once-weekly dosing, meaning the body adjusts both on the way in and on the way out over a similar timeframe. The NHS semaglutide medicines page corroborates this general picture and is the most accessible reference for patients wanting to understand the medicine's behaviour.

For the newer higher-dose 7.2mg Wegovy pen, approved by the MHRA on 14 April 2026, no separate elimination data has been published that meaningfully changes the half-life estimate. The molecule is the same; the dose is higher. A longer time to reach full elimination after stopping could apply at higher maintenance doses, but prescribers will advise based on individual treatment history rather than blanket rules. If you want to understand how long Wegovy stays in your system at a specific dose, your prescriber is the right person to ask. Speak to our prescribers through a free consultation if you're considering starting, stopping or changing treatment.