How much weight did people lose on GLP-1 medicines in clinical trials? Choose a medicine and dose, enter your starting weight, and see the trial average applied to you.
GLP-1 weight loss calculator
See what the average participant lost in each medicine's main clinical trial, applied to your starting weight.
Trial averages are not a prediction. Results vary widely between people, and trials included diet and activity counseling. Most people regain weight if they stop treatment. Talk to your clinician about realistic goals.
How this calculator works
It uses the average percentage of body weight lost in each medicine’s main trial: SURMOUNT-1 for Zepbound (15.0%, 19.5% and 20.9% at 5, 10 and 15 mg over 72 weeks), STEP 1 for the Wegovy injection (14.9% over 68 weeks), OASIS 4 for the Wegovy pill (13.6% over 64 weeks) and SCALE for Saxenda (8.0% over 56 weeks). Participants also received diet and activity counseling.
Common questions
How much weight can you lose on Zepbound?
In SURMOUNT-1, adults on the highest dose (15 mg) lost an average of about 21% of body weight over 72 weeks. Individual results varied widely.
How much weight can you lose on Wegovy?
In STEP 1, adults on the Wegovy injection lost an average of 14.9% of body weight over 68 weeks. In OASIS 4, the Wegovy pill produced 13.6% over 64 weeks.
Is the trial average what I will lose?
Not necessarily. Averages hide a wide range: some people lose much more, some much less. Weight is usually regained if treatment stops.
Sources
- Jastreboff AM, et al. SURMOUNT-1. N Engl J Med. 2022. pubmed.ncbi.nlm.nih.gov
- Wilding JPH, et al. STEP 1. N Engl J Med. 2021. pubmed.ncbi.nlm.nih.gov
- Novo Nordisk. Wegovy pill FDA approval and OASIS 4 results (Dec 22, 2025). www.novonordisk.com
- Pi-Sunyer X, et al. SCALE Obesity and Prediabetes (liraglutide 3.0 mg). N Engl J Med. 2015. pubmed.ncbi.nlm.nih.gov
More free tools: see all GLP-1 tools. This tool provides general information, not medical advice.