This article is educational and does not replace medical advice. Prescription medication requires review by a licensed clinician and, when appropriate, a valid prescription. Compounded medications are not FDA-approved, and the FDA does not verify their safety, effectiveness or quality before marketing. Treatment eligibility is an individual clinical decision.
Released: ·Last reviewed: ·Methodology v4.1
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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 were re-read on 15 October 2026: NovoCare’s Wegovy page and Lilly’s Zepbound savings page. Foundayo prices are carried from LillyDirect pages archived 25 September 2026, because lilly.com blocked automated reads. Figures captured from telehealth provider websites carry the date we read that provider’s page, which may be earlier; where it is, the row or a dated notice says so. We do not restamp a figure we have not re-read.