Weight Regain After Stopping Tirzepatide (Zepbound, Mounjaro): What the Trials Show

If you stop tirzepatide (Zepbound or Mounjaro), most of the weight comes back. The best evidence is a randomized withdrawal trial, SURMOUNT-4. People who had lost an average of 20.9% of their body weight on tirzepatide were switched to placebo and regained 14.0% over the next year, while those who kept taking it lost another 5.5%.^[1] Two things in the newer data matter just as much. First, blood pressure, cholesterol and blood sugar rose roughly in step with the regain.^[2] Second, SURMOUNT-MAINTAIN found that stepping down to 5 mg held on to much more weight than stopping.^[3] This article covers how fast the weight returns after your last dose, who regains the most, and what options you have besides stopping completely.

The short answer

• Most people regain a large share of the weight. In SURMOUNT-4, people switched to placebo regained 14.0% of their body weight over 52 weeks. Only 16.6% kept at least 80% of their earlier loss, compared with 89.5% of those who stayed on tirzepatide.^[1]
• Not all of it returns within a year. The placebo group was still 9.9% below its starting weight at week 88, compared with 25.3% for people who kept taking the drug.^[1] The weight returns faster than most people expect, but it had not fully returned by the end of the trial.
• The health benefits fade with the weight. People who regained 75% or more of their loss saw waist size go up by 14.7 cm and systolic blood pressure by 10.4 mmHg. People who regained less than 25% kept most of their improvements.^[2]
• A lower dose works better than stopping. In SURMOUNT-MAINTAIN, people who stepped down to 5 mg ended at −16.6% from baseline, compared with −21.9% for those who stayed on their full dose and −9.9% for those switched to placebo.^[3]

SURMOUNT-4: what happened when tirzepatide was withdrawn

SURMOUNT-4 (Aronne, JAMA 2024) is the trial built to answer this question.^[1] In the first phase, 783 adults with obesity, or overweight plus a weight-related condition (but not diabetes), took open-label tirzepatide at their maximum tolerated dose (10 or 15 mg weekly) for 36 weeks. In that time they lost an average of 20.9% of their body weight. Next, 670 participants were randomly assigned 1:1, either to keep taking tirzepatide or to switch to placebo, for another 52 weeks. Neither the participants nor the investigators knew who was on which. Both groups kept getting diet and physical-activity counseling throughout.

The authors concluded that withdrawing tirzepatide led to substantial regain of lost weight, whereas continued treatment “maintained and augmented” the original loss.^[1] For a typical participant, the net loss shrank from about 21% to about 10% of starting weight. That works out to roughly half of the lost weight coming back within a year. The trial ended at week 88, so it doesn't show whether the remaining loss would also have disappeared over a longer period.

How much each person regained, and why it matters for health

An average hides how much people differed. A 2026 post hoc analysis in JAMA Internal Medicine (Horn et al.) took the 308 placebo-switched SURMOUNT-4 participants who had lost at least 10% during the lead-in. It grouped them by how much of that loss they had regained by week 88.^[2]

About four in five people regained at least a quarter of their lost weight within a year, and more than half regained at least half of it.^[2] Non-HDL cholesterol and fasting insulin followed the same pattern. In the group that regained the least, non-HDL cholesterol was essentially unchanged (−0.4%). In the groups that regained the most, it rose by 8.4% and 10.8%.^[2] The authors concluded the findings “underscore the importance of continued obesity treatment.” That fits a broader finding: the health benefits of tirzepatide come from keeping the weight off, not from having lost it once.

One detail is easy to miss. Systolic blood pressure went up by 6.8 mmHg even in the group that kept almost all its weight off.^[2] Some of tirzepatide's effect on blood pressure seems to go away when the drug does, regardless of weight. If you have high blood pressure and stop, recheck it within a few weeks rather than waiting until you notice weight coming back.

How fast does the weight come back?

The Zepbound label gives tirzepatide's elimination half-life as about 5–6 days in people with overweight or obesity.^[4] Using the usual rule of thumb that a drug is mostly gone after about five half-lives, almost all of it is cleared within about a month of the last injection. That is why many people notice their appetite and “food noise” coming back within the first few weeks, well before the scale moves much.

Two 2026 meta-analyses estimate how fast the weight returns:

• West et al., BMJ 2026 pooled 37 studies (9,341 participants) of all weight-management drugs. The average regain after stopping was 0.4 kg per month. Cardiometabolic markers were projected to return to baseline within about 1.4 years. Weight came back faster after stopping a drug than after a behavioral program ended, by 0.3 kg per month, even after accounting for how much weight people had lost.^[5]
• Kow et al., Endocrinol Diabetes Metab 2026 looked only at semaglutide and tirzepatide (6 studies, 1,776 participants). It estimated regain at about 1.0 kg per month, with half the lost weight back by about 7.5 months. Tirzepatide looked a little faster than semaglutide before adjustment, but there was no clear difference between the drugs after adjustment. Larger initial weight loss tended to mean faster regain. The authors warn that anything beyond 52 weeks is a model projection, not something they observed.^[6]

For the brain and hormone side of this (why hunger can come back stronger than before), see our explainer on rebound hyperphagia after stopping a GLP-1.

Stepping down instead of stopping: SURMOUNT-MAINTAIN

Until 2026, there was no trial data on lowering the dose instead of stopping. SURMOUNT-MAINTAIN (Horn, The Lancet 2026) was a 112-week trial run at 20 US sites.^[3] Participants took their maximum tolerated dose (10 or 15 mg) for 60 weeks. Then 378 of them were randomly assigned 3:3:2 to stay on that dose, step down to 5 mg, or switch to placebo for 52 weeks. From week 84 onward, anyone who regained more than half of their lost weight could get “rescue” tirzepatide.

Staying on the full dose worked best. The 5 mg step-down kept just over half of the difference between the full-dose and placebo groups, and it cut the number of people who regained enough to need rescue therapy to well under half the placebo rate.^[3] The authors called the lower dose “a valuable alternative to discontinuation,” and added that individual responses varied. For anyone stopping because of cost or side effects, a lower maintenance dose now has randomized evidence behind it. A gradual taper toward zero still does not. Our Zepbound maintenance dose guide and step-down protocol evidence review cover how to set this up with your prescriber.

If you have prediabetes or take Mounjaro for diabetes

The 3-year SURMOUNT-1 extension followed 1,032 people with obesity and prediabetes for 176 weeks on tirzepatide or placebo, then 17 more weeks off treatment.^[8] While on treatment, 1.3% of the tirzepatide group developed type 2 diabetes, compared with 13.3% on placebo. Seventeen weeks after stopping, the tirzepatide group's figure had risen to 2.4% (13.7% for placebo).^[8] Most of the protection was still there after four months, but the number had started going up. In SURMOUNT-4, HbA1c also rose most in the people who regained the most weight.^[2]

If you take Mounjaro for type 2 diabetes, stopping is mainly a blood-sugar question, not a weight question. Don't stop without a plan from your prescriber for what will replace it. For the brand differences, see Mounjaro vs Zepbound.

If you're stopping anyway: a practical plan

1. Ask about a lower dose before stopping completely. SURMOUNT-MAINTAIN's 5 mg arm is the only maintenance strategy short of the full dose that has randomized evidence behind it.^[3]
2. If cost is the reason, compare prices first. Cash prices for brand Zepbound vary a lot depending on where you buy it. See how to get tirzepatide online before giving up on a drug that is working.
3. Weigh yourself weekly and agree on a restart point. SURMOUNT-MAINTAIN offered rescue therapy at 50% regain.^[3] Agreeing on a threshold with your prescriber ahead of time means you won't have to decide under pressure later.
4. Recheck blood pressure, lipids and HbA1c. These can go up within months of stopping, and blood pressure can rise even if your weight holds.^[2][5]
5. If pregnancy is the reason, follow the label. The Zepbound label says to stop when pregnancy is recognized.^[4] For how far ahead to stop before trying to conceive, see GLP-1 pregnancy washout evidence.
6. Don't just pick up your old dose after a long break. The label only covers missed doses: take it within 4 days, otherwise skip it.^[4] It doesn't say how to restart after weeks off. Ask your prescriber what dose to restart at so you limit the GI side effects of starting again.

For a broader look at the stop, step down or continue decision, see our life-after-GLP-1 maintenance hub and guide to tapering off a GLP-1.

The bottom line

Tirzepatide treats obesity for as long as you take it. It doesn't cure it. Randomized data show that stopping brings back roughly half of the lost weight within a year, and more for many people. Blood pressure, cholesterol and blood sugar rise along with it.^[1][2] A lower maintenance dose keeps much more of the benefit than stopping does.^[3] If you're thinking about coming off tirzepatide, ask your prescriber about a lower dose first.