Why do people stop taking weight loss drugs?
Plenty of people end up stopping weight loss medication (also known as GLP-1 receptor agonists). For some, the side effects are just too much to handle: nausea, stomach pain, diarrhoea, constipation or heartburn. For others, the monthly cost or the constant supply issues make it impossible to keep going.
Some people stop once they’ve hit their goal weight, hoping they can maintain it on their own. And sometimes, it’s simply a personal choice to come off the medication.
The reality is that people stop weight loss drugs for lots of reasons - side effects, cost, supply issues or reaching a goal weight. If you’re unsure when to stop weight loss injections, speak to your clinician about a taper plan instead of stopping suddenly.
Related: What is Ozempic? Uses, how it works and side effects
Medical advice and individual circumstances
If you’re considering stopping, speak to your doctor first. Your clinician can explain how to stop weight loss injections safely (usually by tapering) and what monitoring you’ll need, like your blood pressure or blood sugar.
“Stopping treatment with GLP-1s suddenly does carry a risk of regaining weight,” says Dr Daniel. “Because these medications regulate glucose metabolism, stopping suddenly may also cause your blood sugar to rise temporarily - potentially causing excessive thirst, blurred vision or fatigue.
“There isn’t much guidance around on how to stop or taper off GLP-1s. Evidence suggests that slowly tapering down your dose once you’ve reached your goal weight is the most effective ‘exit strategy’ and reduces the likelihood of regaining weight post-treatment. So it’s better to taper off gradually, by slowly decreasing your dose with the help of a clinician, than stop suddenly.”
When to stop weight loss injections?
There isn’t a single right moment. Most clinicians suggest stopping weight loss injections once you’ve reached a weight that feels realistic to maintain and you’ve had a period of stability. Rather than quitting suddenly, agree a taper plan so your dose reduces gradually. That gives your appetite time to readjust and helps you keep hold of the routines you’ve built.
Good signs you might be ready to discuss stopping:
you’ve maintained a similar weight for several months
you’re consistently eating regular, balanced meals with enough protein
you’re moving your body most days and doing some strength work each week
you feel confident you can keep these habits going without the medication
If side effects, cost or supply issues are pushing you to stop sooner, speak to your prescriber first. A planned taper and a check-in schedule is far kinder on your body than going cold turkey.
Related: Ozempic vs Mounjaro vs Wegovy - how are they different?
What happens when you stop weight loss injections or tablets?
Most people see some regain after stopping - this is true whether you’ve used weekly weight loss injections like Ozempic or Mounjaro, or prescription weight loss drugs in tablet form.
“Not always, but it can happen,” says Dr Daniel. “One study found that people who were switched to a placebo after 36 weeks of treatment on tirzepatide (Mounjaro) had an average weight regain of 14% over the course of the following year (compared to a further loss of 5.5% for people who continued treatment).
“There are a few factors that can contribute to regaining weight after stopping weight loss treatment. The obvious one is that the drug isn’t in your system to support you anymore. So if you were taking a medication that helped to reduce cravings and lower your appetite, with these effects no longer present, you might unconsciously gravitate towards larger portion sizes or less healthy snacking habits.
“Another factor is that you might have stopped treatment before fully embedding supporting lifestyle habits, such as eating healthy or exercising regularly.
“So if increased physical activity and a healthy diet aren’t a cemented part of your routine, you’re more dependent on the treatment to help you stay at a lower weight - and when you stop treatment in this case, your weight is more likely to increase again.”
Medication and weight regain
Medication | Active ingredient | Average weight loss | What happens after stopping |
Wegovy | Semaglutide | 10 to 15% | Studies suggest many people regain around two-thirds of the weight lost within a year of stopping treatment, though this varies between individuals |
Mounjaro | Tirzepatide | Up to 20% | Similar regain expected once the drug wears off |
Wegovy, Ozempic and Mounjaro - what to expect after stopping
It’s common to notice more thoughts about food, bigger hunger and a shift in portion sizes after stopping Wegovy or Ozempic (both semaglutide) and Mounjaro (tirzepatide). These are the best-known weight loss drug Ozempic and weight loss drug Mounjaro queries we see, and the pattern is similar across them: as the medicine leaves your system, the appetite-regulating effect eases off.
What people often report:
Weeks one to four: appetite gradually returns, especially late afternoon and evening. Planning meals and snacks helps.
Weeks four to eight: hunger may feel noticeably louder. This is when strength training, protein-rich meals and sleep routine make the biggest difference.
Beyond eight weeks: your new baseline becomes clearer. Some regain is normal; keeping movement and meal structure in place helps limit it.
If your goal is to maintain, aim for slow and steady: protein at each meal, a couple of strength sessions a week, regular bedtimes and support from your GP or a dietitian if you can access one.
How quickly does it happen?
“It can vary depending on the treatment or dose you’re using, but weight loss injections you take weekly (like Mounjaro or Wegovy) tend to peak in the body at around one to three days after injecting each dose,” explains Dr Daniel.
“Over the course of the following week, the levels in your system will gradually start to decrease. After your final dose, it takes about four to seven weeks for these drugs to completely leave your system - but again this can vary.
“So, while everyone is different, you might start to notice the effects of the drug wearing off as you come up to the one-month mark.
“For daily injections like Saxenda or Nevolat, the half-life is shorter. So these peak at around 11 hours after you inject each dose, and they’re more quickly eliminated from the body. After stopping these medications, you’ll notice the effects wear off much faster than with weekly injections.”
In short: yes, you can gain weight after stopping weight loss injections, but a gradual taper plus lifestyle support can reduce the rebound.
Related: What is Mounjaro? Uses, how it works and side effects
Do most people regain all the weight they’ve lost?
Not usually all of it, but many do regain a large share. Research suggests people often put back around two-thirds within a year. Early research suggests much of the regained weight is fat rather than muscle, but more long-term studies are needed.
Is the weight regain the same for everyone?
No, it varies. While studies show a strong trend, factors like genetics, lifestyle and overall health all play a role in whether you regain weight and how much you regain.