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What is the average GLP-1 weight loss?

This tool shows what the average weight-loss percentages reported in clinical trials for Wegovy, Zepbound, and Saxenda would mean at your starting weight. Enter your starting weight to see the corresponding numbers. These are trial averages, not a prediction of your individual results.

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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

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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 to review with your prescriber

None of the following is a recommendation, and none of it is a proven way to restart weight loss. These are the things a prescriber can look at with you if your result is not what you expected.

Whether your current dose still suits you

The Zepbound label asks prescribers to consider treatment response and tolerability when selecting the maintenance dosage. Some people keep responding well at a lower dose, and a higher one is not automatically better.

Whether a different medication is worth considering

SURMOUNT-5 compared tirzepatide and semaglutide directly and found 20.2% against 13.7% at 72 weeks. That trial started people on one treatment or the other from the beginning, so it shows the two differ on average. It did not study switching after a stall, and it does not show that a switch restarts one.

Whether adding something has been tested

The one randomized test of adding a second medication after a year of treatment gave phentermine on top of liraglutide to 45 people for 12 weeks. The added-medication group lost 1.6% against 0.1% on placebo, which did not reach statistical significance. Prescribers do combine medications, but the published evidence for adding one after a stall is thin.

Protein and resistance training, for muscle

Reviewing the trial evidence, Mechanick and colleagues estimate participants lost 10% or more of their muscle mass over 68 to 72 weeks, inferred from lean-mass measurements rather than measured muscle directly. Adequate protein and resistance training are what the guidance recommends for holding on to that tissue. That is about protecting muscle, not a way to restart weight loss. The protein calculator and meal builder can help you hit a daily target.

Everything else that affects the same result

Intake can drift upward as early appetite suppression settles. Alcohol, short sleep and untreated thyroid disease can each work against the same result, and the Endocrine Society's guideline notes that many medications given for diabetes, depression and other chronic conditions promote weight gain. None of these is necessarily the reason for your own plateau. Fluids and fiber are worth keeping steady, which the water calculator and fiber calculator cover.

Other medications, and what is coming

Other approved weight medications exist, and several newer ones are in late-stage trials. Comparing them properly means comparing what each was tested on, which is what the medication guide is for. Bariatric surgery remains the most effective option on long-term averages and can work alongside these medications, which is a fair thing to raise if you have been at this a while.

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. 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.
  5. 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.
  6. 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.
  7. 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.
  8. Qaseem A, Cross JT Jr, Harrod CS, Owens DK. Pharmacologic treatments with lifestyle modifications in nonpregnant adults with overweight or obesity in outpatient settings: a living clinical guideline from the American College of Physicians (April 2026). Annals of Internal Medicine. 2026;179(8):1177–1185. doi:10.7326/annals-25-02714. Source of the treatment ranking, the guidance to switch rather than add on an inadequate response, and both safety cautions.
  9. Damen JAA, Idema DL, Vernooij RWM, et al. Benefits and harms of pharmacologic treatments in adults with overweight or obesity: a living systematic review and network meta-analysis for the American College of Physicians. Annals of Internal Medicine. 2026;179(8):1140–1155. doi:10.7326/annals-24-03764. The 69-trial, 112,511-participant evidence review behind the ranking, and the source for semaglutide and tirzepatide leading it.
  10. Alexander L, Purnell JQ, Burridge K, et al. Joint TOS/OMA/OAC expert guidance statement on the pharmacological management of United States adults with overweight or obesity using the GRADE approach. Obesity. 2026;34(4):851–870. doi:10.1002/oby.70164. Source of the strong recommendation for naltrexone-bupropion and for continuing medication through maintenance.
  11. 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.
  12. 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.
  13. Apovian CM, Aronne LJ, Bessesen DH, et al. Pharmacological management of obesity: an Endocrine Society clinical practice guideline. The Journal of Clinical Endocrinology & Metabolism. 2015;100(2):342–362. doi:10.1210/jc.2014-3415. Source for common prescriptions that promote weight gain.
  14. 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.
  15. Zepbound (tirzepatide) Prescribing Information: Dosage and Administration. Eli Lilly. Current label at DailyMed. Source of the instruction to consider treatment response and tolerability when selecting the maintenance dosage.
  16. Jastreboff AM, Kaplan LM, Frías JP, et al. Triple-hormone-receptor agonist retatrutide for obesity: a phase 2 trial. New England Journal of Medicine. 2023;389(6):514–526. doi:10.1056/NEJMoa2301972. Source of the 24.2% average at 48 weeks against 2.1% on placebo, in 338 adults.
  17. Brosnihan P, Luce MS, Yetasook AK, Perez C, Scharf KR, Aly S. Great debates: undergoing the knife versus pill-popping: the comparative efficacy and cost-effectiveness of bariatric surgery and GLP-1 receptor agonists in the management of obesity. The American Surgeon. 2025;91(10):1587–1593. doi:10.1177/00031348251337145. Source of the 23% sleeve gastrectomy and 27% gastric bypass ten-year figures, and of the under-1% uptake among eligible people.
  18. Mechanick JI, Butsch WS, Christensen SM, et al. Strategies for minimizing muscle loss during use of incretin-mimetic drugs for treatment of obesity. Obesity Reviews. 2025;26(1):e13841. doi:10.1111/obr.13841. Source for the estimate that trial participants lost 10% or more of their muscle mass over 68 to 72 weeks.