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GLP-1 weight-loss results: what trials show
Quick answer
In pivotal trials, semaglutide 2.4 mg produced about 15% average body-weight reduction and tirzepatide up to about 21% over roughly 68–72 weeks. Individual results vary widely, and trial averages are not a promise.
Trial averages
STEP (semaglutide) and SURMOUNT (tirzepatide) are the pivotal weight-management programs. Averages differ by molecule and dose; see the semaglutide and tirzepatide guides.
Typical timeline
Meaningful loss usually appears over months, not weeks, and tracks dose escalation. Plateaus are common. Maintenance requires ongoing treatment for most patients.
Frequently asked questions
How much weight will I lose on a GLP-1?
Trial averages range from roughly 15% to 21% of body weight, but your result depends on dose, adherence, and individual factors. Averages are not guarantees.
Sources
- U.S. Food and Drug Administration — labels and safety communications.
- Peer-reviewed clinical trials cited above.
- Our methodology and medical review policy.
How the dates on this page work. Manufacturer self-pay prices — NovoCare and LillyDirect — were re-read on the manufacturers’ own published price guides on 4 August 2026. Figures captured from third-party provider websites carry the date we read that provider’s page, which may be earlier; where it is, the row says so. We do not restamp a figure we have not re-read.