GLP-1 trial results
What GLP-1 trials measured.
Average weight loss in STEP-1 (semaglutide) and SURMOUNT-1 (tirzepatide), the trials behind the FDA-approved brand-name products — with their sources, and without a prediction for you.
Average results in two clinical trials
| Trial | Medication studied | Length | Average on medication | Average on placebo |
|---|---|---|---|---|
| STEP-1 (NEJM 2021) | semaglutide 2.4 mg (Wegovy®) | 68 weeks | −14.9% | −2.4% |
| SURMOUNT-1 (NEJM 2022) | tirzepatide 15 mg (Zepbound®) | 72 weeks | −20.9% | −3.1% |
Two separate trials of FDA-approved brand-name products, not REMEVi averages and not a prediction for you. Compounded medications are not FDA-approved and were not studied in these trials. Individual results vary.
Sources: STEP-1 — Wilding et al., NEJM 2021 · SURMOUNT-1 — Jastreboff et al., NEJM 2022
How to read these numbers
Semaglutide — STEP-1
Average weight loss of 14.9% over 68 weeks with semaglutide 2.4 mg (Wegovy®), against 2.4% with placebo, alongside diet and activity counseling.
Tirzepatide — SURMOUNT-1
Average weight loss of 20.9% over 72 weeks with tirzepatide 15 mg (Zepbound®), against 3.1% with placebo. A separate trial, so the two figures are not a head-to-head comparison.
What these figures are not
- Not REMEVi patient averages
- Not a prediction for you — individual results vary with dose and health
- Not results for compounded medications, which are not FDA-approved
- Available in English and Spanish
GLP-1 trial results — Frequently Asked Questions
In STEP-1, adults taking semaglutide 2.4 mg (Wegovy®) lost 14.9% of body weight on average over 68 weeks (placebo 2.4%). In SURMOUNT-1, adults taking tirzepatide 15 mg (Zepbound®) lost 20.9% on average over 72 weeks (placebo 3.1%). These are trial results for FDA-approved brand-name products, not REMEVi averages. Compounded medications were not studied in these trials, and individual results vary.
A trial average is not a forecast for one person. Results in those trials varied widely with dose, how long people stayed on treatment, and their health, diet and activity. Turning an average into a personal weight forecast would suggest a precision the trials do not support, so this page shows the trial results themselves, with their sources.
Most guidelines consider about 1–2 pounds (roughly 0.5–1 kg) per week to be a safe, sustainable rate. GLP-1 medications are titrated up gradually over several weeks, so weight loss usually starts slowly and builds as the dose increases. Faster is not better — gradual loss helps preserve muscle and is easier to maintain.
Some weight regain is common after stopping a GLP-1, because the medication's appetite effects end when treatment ends. Many people maintain results by continuing a lower maintenance dose and keeping the nutrition and activity habits built during treatment. Your licensed provider can help plan a long-term, sustainable approach.
No. This page is for education only and is not medical advice or a treatment recommendation. Whether a GLP-1 medication is appropriate for you is a decision made with a licensed provider after reviewing your full health history.
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