- A plateau is the expected pattern: on semaglutide 2.4 mg (Wegovy), average weight loss levelled off around week 60, then held through two years in STEP 5.1
- On tirzepatide (Zepbound), adults with prediabetes in a three-year SURMOUNT-1 analysis reached their lowest weight after about 21 to 23 months on average.5
- A plateau does not mean the medicine stopped working. At week 60, people on semaglutide were still eating about 270 kcal less than placebo at a test meal.6
When does weight loss stop on semaglutide?
STEP 1 followed 1,961 adults without diabetes on semaglutide 2.4 mg or placebo for 68 weeks. Average weight loss was 14.9% on semaglutide vs 2.4% on placebo.2 The authors of the later STEP 5 trial noted that in STEP 1 and STEP 2, weight reductions "appeared to plateau around week 60."1
STEP 5 then asked what happens after the plateau. It followed 304 adults without diabetes for two years. Weight came down until about week 60 and then stayed down.1
In other words, the plateau was a new, lower resting point, not the start of a slide back. For the full long-term picture, see our article on long-term GLP-1 results.
Zepbound plateau: when does tirzepatide level off?
In SURMOUNT-1, 2,539 adults without diabetes took tirzepatide 5, 10 or 15 mg, or placebo. At week 72, average weight change was −15.0%, −19.5% and −20.9% on the three doses, vs −3.1% on placebo.3
The 1,032 participants who also had prediabetes were assigned to treatment for 176 weeks, a little over three years. At that point, average weight change was −12.3%, −18.7% and −19.7% on the three doses, vs −1.3% on placebo.4
A 2026 analysis of that group looked at each person's lowest weight, or nadir. It included people who took at least 75% of their doses and had lost at least 5% at their low point.5
| Tirzepatide dose | Average time to lowest weight | Reached lowest weight by week 72 |
|---|---|---|
| 5 mg | 21.1 months | 48.9% |
| 10 mg | 21.1 months | 46.4% |
| 15 mg | 22.6 months | 38.8% |
So more than half of these people kept losing weight after week 72. After their low point, some weight crept back for most. Across doses, 70% regained less than 5% of their body weight by week 176, 22% regained 5% to under 10%, and 8% regained 10% or more.5 Several authors work for the drug's maker, and the analysis was not planned in advance.
Why does weight loss plateau on a GLP-1?
A smaller body needs less energy to run and to move. As weight comes down, the gap between what you eat and what you burn shrinks, until the two meet at a new, lower weight. This happens with any way of losing weight, with or without medication.
The question is whether the medicine wears off. A 60-week trial in 120 adults with overweight or obesity measured this directly.6 At a free-choice lunch, people on semaglutide 2.4 mg ate less than the placebo group at every check:
Hunger ratings told a different story. At week 20, the semaglutide group reported less hunger and less food preoccupation, but by weeks 40 and 60 their appetite ratings no longer differed from placebo.6 The authors concluded that eating fewer calories is a central way semaglutide both causes and maintains weight loss, even when people feel the effect less.
Two earlier mechanism studies fit this picture. After 12 weeks of semaglutide 1.0 mg, resting metabolic rate adjusted for lean mass did not differ from placebo, while total intake across a day of free meals was 24% lower.7 In adults with type 2 diabetes, tirzepatide 15 mg cut lunch intake by about 310 kcal more than placebo at week 28.8
How much does the plateau point vary?
Averages hide a wide spread. Some people plateau at 5% weight loss and others at 25%.
| Lost at least | STEP 1: semaglutide 2.4 mg (week 68) | SURMOUNT-1: tirzepatide 15 mg (week 72) |
|---|---|---|
| 5% | 86.4% | 91% |
| 10% | 69.1% | – |
| 15% | 50.5% | – |
| 20% | – | 57% |
On placebo, 31.5% in STEP 1 and 35% in SURMOUNT-1 still lost at least 5%, with diet and activity support alone.2,3 Your own plateau may land above or below the trial average, and that alone does not tell you whether the medicine is working for you.
Is it a real plateau or just a slow few weeks?
Day-to-day weight moves with water, salt, bowel habits and the menstrual cycle. A flat week or two is common in the middle of steady loss. A real plateau shows up as a flat trend over several weeks. Logging weight regularly and looking at weekly averages makes the difference much easier to see; here is what research says about tracking on GLP-1s.
GLP-1 plateau: what to do
- Talk to your prescriber. Any change in dose or treatment is their decision, based on your health, side effects and goals. It is not something to decide alone.
- Bring data. Your weight trend, dose history and side effects over the past few months make the conversation far more useful.
- Protect muscle. Protein and strength training matter whether you are losing or holding; see how much protein the research suggests.
- Know what stopping does. The trials show most lost weight returns after the medicine stops; here is what they found.
Common questions
When does weight loss stop on semaglutide?
In the STEP 1 and STEP 2 trials, weight loss on semaglutide 2.4 mg (Wegovy) appeared to plateau around week 60, according to the authors of STEP 5. In STEP 5, adults without diabetes were still 15.2% lighter on average at week 104, vs 2.6% on placebo.
Is a Zepbound plateau normal?
Yes, a plateau is the usual pattern. In a three-year SURMOUNT-1 analysis of adults with obesity and prediabetes taking tirzepatide (Zepbound), people reached their lowest weight after about 21 to 23 months on average, and 70% then regained less than 5% of their body weight by week 176.
Why does weight loss plateau on a GLP-1 if the medicine is still working?
As weight falls, the body needs less energy, so intake and needs eventually meet at a new, lower weight. In a 60-week trial, adults on semaglutide 2.4 mg still ate about 270 kcal less than placebo at a test lunch at week 60, which suggests the medicine keeps working at the plateau.
GLP-1 plateau: what to do?
Bring several weeks of weight data to your prescriber, who decides on any change in treatment. Results vary widely: in STEP 1, 86.4% of adults on semaglutide 2.4 mg lost at least 5% of their weight by week 68, and 50.5% lost at least 15%.
Sources
- Garvey WT, Batterham RL, Bhatta M, et al. Two-year effects of semaglutide in adults with overweight or obesity: the STEP 5 trial. Nat Med. 2022;28(10):2083-2091. PubMed · Full text (PMC)
- Wilding JPH, Batterham RL, Calanna S, et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1). N Engl J Med. 2021;384(11):989-1002. PubMed · doi:10.1056/NEJMoa2032183
- Jastreboff AM, Aronne LJ, Ahmad NN, et al. Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1). N Engl J Med. 2022;387(3):205-216. PubMed · doi:10.1056/NEJMoa2206038
- Jastreboff AM, le Roux CW, Stefanski A, et al. Tirzepatide for Obesity Treatment and Diabetes Prevention. N Engl J Med. 2025;392(10):958-971. PubMed · doi:10.1056/NEJMoa2410819
- Aronne LJ, Vincent RP, Klein KR, et al. Evaluation of clinical relevance of weight nadirs and weight regain during 3 years of treatment with tirzepatide in participants with obesity or overweight and prediabetes. Obes Pillars. 2026;20:100333. PubMed · Full text (PMC)
- Tronieri JS, Allison KC, DeRouen K, et al. Short- and long-term effects of semaglutide 2.4 mg on energy intake, appetite, and food reward: a 60-week, double-blind randomized controlled trial. Am J Clin Nutr. 2026;124(2):101403. PubMed · Full text (PMC)
- Blundell J, Finlayson G, Axelsen M, et al. Effects of once-weekly semaglutide on appetite, energy intake, control of eating, food preference and body weight in subjects with obesity. Diabetes Obes Metab. 2017;19(9):1242-1251. PubMed · Full text (PMC)
- Heise T, DeVries JH, Urva S, et al. Tirzepatide Reduces Appetite, Energy Intake, and Fat Mass in People With Type 2 Diabetes. Diabetes Care. 2023;46(5):998-1004. PubMed · Full text (PMC)
