Your numbers

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In the trial

This is education, not medical advice

Nothing here is a recommendation to start, stop, switch or change the dose of any medication. These are published group averages, and the right target for you depends on your health history, your other conditions and what your prescriber finds. Bring the numbers to that conversation rather than acting on them alone.

Percent of body weight lost

—%

About the number

Every figure here is a mean from a controlled trial, and results in those trials varied widely around it. The trials also differ from each other in length, in dose, in who was enrolled, and in how much diet and exercise support everyone received, so a comparison across two of them is a rough one.

Milestones from your starting weight

How the number is built

Percent lost is your weight lost divided by your starting weight. It is the measure the trials report, which is what makes a comparison across two different bodies possible at all.

How to read your comparison

The number this tool shows you is a mean from a published trial, applied to the weight you entered. A mean is not a goal, a target, or an expected endpoint. It is the average of a group of people who were not you, in a study with its own dose, duration and support.

Results varied widely around every average

In STEP 1, 50% of participants lost 15% or more of their body weight while about one in seven did not reach 5%, all on the same dose and protocol. A single average hides that spread in both directions.

Being below an average is not a verdict

If your percentage is under the figure for your medication, that is information worth bringing to an appointment rather than a measure of how hard you have tried.

Trials are not directly comparable to each other

These trials differ in length, dose, who was enrolled and how much diet and exercise support everyone received. Comparing one trial's number with another's is rough, and comparing either with your own result is rougher still.

Why weight loss may slow

When you lose weight, your body adapts. It may burn fewer calories, increase hunger signals, and make further weight loss harder. Rosenbaum and Leibel found these responses in both lean people and people with obesity, which tells us this is normal human physiology, not a lack of effort.

Obesity can still require ongoing treatment. In the STEP 1 extension, participants regained about two-thirds of the weight they had lost within a year of stopping semaglutide and the lifestyle support. The treatment had stopped, but the condition it was treating had not disappeared.

Your body burns less energy at a lower weight

A smaller body naturally needs fewer calories. Weight loss can also cause your body to conserve energy and increase hunger. This means the same food and activity habits that helped you lose weight earlier may eventually maintain your weight instead, causing weight loss to slow or stop.

A plateau does not always mean the medication has stopped working

A plateau can happen even while a GLP-1 medication is still having an effect. As weight decreases, the body generally needs less energy, and changes in appetite, activity, and energy use can slow further weight loss. Individual responses vary, though, and a prescriber can help determine whether the medication is still providing benefit.

Appetite signals can stay changed for at least a year

Sumithran and colleagues followed people for one year after diet-induced weight loss and found ghrelin still elevated and leptin still suppressed at that point. That study did not involve GLP-1 treatment, and it did not follow people beyond a year, so it describes what happens after weight loss rather than what a medication does to those signals.

Trial participants plateaued too, and earlier than you might expect

A post-hoc analysis of SURMOUNT-1 and SURMOUNT-4 measured when tirzepatide participants stopped losing. Median time to plateau ran from about 24 weeks in the overweight group to about 36 weeks in the highest BMI groups, and by week 72 roughly 88 to 90% had reached one.

Higher doses, younger age and female sex were associated with plateauing later. Timing varied between individuals, so these are medians rather than a schedule.

What has not been tested

If your result has slowed, the usual next moves are raising the dose, switching medication, or adding a second one. All three are plausible, and prescribers do all three. None of them has been tested in people who have already stopped losing. There is no published research yet on how to break a plateau on a GLP-1. This page will be updated as soon as there is.

Raising the dose

In SURMOUNT-1, groups assigned higher doses of tirzepatide lost more on average, 15.0% at 5 mg against 20.9% at 15 mg. Those people were put on their dose at the start. No trial has taken people who stopped losing and raised it to see what happens.

The closest finding is that higher doses were associated with reaching a plateau later, which is an observation from inside the trials rather than a test of escalating.

Switching medication

SURMOUNT-5 compared tirzepatide with semaglutide directly and found 20.2% against 13.7% at 72 weeks. Everyone in it started fresh on one or the other. It shows the two differ on average. It does not show that moving from one to the other restarts a stalled result.

Adding a second medication

The only randomized attempt gave phentermine on top of liraglutide to 45 people for 12 weeks, after a year of treatment. The added-medication group lost 1.6% against 0.1% on placebo, which did not reach statistical significance. The rest of the published work on combining is animal studies, trials about maintaining a loss, or expert opinion.

None of this means these are bad ideas, or that they will not work for you. It means nobody has run the study yet, so a prescriber making one of these calls is using judgement and your history rather than following evidence.

Sources

  1. Wilding JPH, Batterham RL, Calanna S, et al. Once-weekly semaglutide in adults with overweight or obesity (STEP 1). New England Journal of Medicine. 2021;384(11):989–1002. doi:10.1056/NEJMoa2032183. Source of the 14.9% Wegovy average, the 2.4% placebo figure, and the 86%, 69% and 50% shares reaching 5%, 10% and 15% loss.
  2. Wilding JPH, Batterham RL, Davies M, et al. Weight regain and cardiometabolic effects after withdrawal of semaglutide: the STEP 1 trial extension. Diabetes, Obesity and Metabolism. 2022;24(8):1553–1564. doi:10.1111/dom.14725. Source of the regain figure after the medication stopped.
  3. Jastreboff AM, Aronne LJ, Ahmad NN, et al. Tirzepatide once weekly for the treatment of obesity (SURMOUNT-1). New England Journal of Medicine. 2022;387(3):205–216. doi:10.1056/NEJMoa2206038. Source of the 15.0%, 19.5% and 20.9% dose averages for Zepbound, the 3.1% placebo figure, and the 57% of the 15 mg group reaching 20% loss.
  4. Pi-Sunyer X, Astrup A, Fujioka K, et al. A randomized, controlled trial of 3.0 mg of liraglutide in weight management (SCALE). New England Journal of Medicine. 2015;373(1):11–22. doi:10.1056/NEJMoa1411892. Source of the 8.0% Saxenda average.
  5. Rosenbaum M, Leibel RL. Adaptive thermogenesis in humans. International Journal of Obesity. 2010;34(Suppl 1):S47–S55. doi:10.1038/ijo.2010.184. Source for the finding that these responses occur in both lean people and people with obesity.
  6. Sumithran P, Prendergast LA, Delbridge E, et al. Long-term persistence of hormonal adaptations to weight loss. New England Journal of Medicine. 2011;365(17):1597–1604. doi:10.1056/NEJMoa1105816. Source for ghrelin and leptin still altered a year after weight loss.
  7. Ryan DH, Yockey SR. Weight loss and improvement in comorbidity: differences at 5%, 10%, 15%, and over. Current Obesity Reports. 2017;6(2):187–194. doi:10.1007/s13679-017-0262-y. Source of the 5% and 10% milestone descriptions.
  8. Lingvay I, Sumithran P, Cohen RV, le Roux CW. Obesity management as a primary treatment goal for type 2 diabetes: time to reframe the conversation. The Lancet. 2022;399(10322):394–405. doi:10.1016/S0140-6736(21)01919-X. Source for a 15% loss having a disease-modifying effect in type 2 diabetes.
  9. Aronne LJ, Horn DB, le Roux CW, et al. Tirzepatide as compared with semaglutide for the treatment of obesity (SURMOUNT-5). New England Journal of Medicine. 2025;393(1):26–36. doi:10.1056/NEJMoa2416394. The head-to-head trial, 20.2% against 13.7% at 72 weeks, in people starting treatment rather than switching after a stall.
  10. Tronieri JS, Wadden TA, Walsh OA, et al. Effects of liraglutide plus phentermine in adults with obesity following 1 year of treatment by liraglutide alone: a randomized placebo-controlled pilot trial. Metabolism. 2019;96:83–91. doi:10.1016/j.metabol.2019.03.005. The only randomized test of adding a second medication after a year of treatment: 45 people, 12 weeks, 1.6% against 0.1%, not statistically significant.
  11. Horn DB, Kahan S, Batterham RL, et al. Time to weight plateau with tirzepatide treatment in the SURMOUNT-1 and SURMOUNT-4 clinical trials. Clinical Obesity. 2025;15(3):e12734. doi:10.1111/cob.12734. Post-hoc analysis. Source of the 24 to 36 week median times to plateau by BMI category, the 88 to 90% who had plateaued by week 72, and the dose, age and sex associations.