Anyone who stays on a GLP-1 medicine long enough reaches a point where the scale stops moving. The trials show the same thing on average: every long trial of these drugs has a weight curve that falls steeply, bends, and flattens. What the trials also show, and what the forum threads rarely mention, is when that bend arrives, whether the flat part holds, and what has actually been tested once people got there.
This page reports that record, read on 26 September 2026. It does not say what one person should do at a plateau; that is a conversation with the prescriber. How long the drugs take to work in the first place is on our how long it takes page.
When the curve flattens
The clearest long view comes from trials that ran well past the usual 68 to 72 weeks:
| Trial | Drug | Who | Result |
|---|---|---|---|
| SELECT | semaglutide 2.4 mg | 17,604 adults with heart disease and overweight or obesity, no diabetes | weight loss continued for about 65 weeks, then sustained to 4 years; −10.2% vs −1.5% at 208 weeks |
| SURMOUNT-1 extension | tirzepatide 5 / 10 / 15 mg | adults with obesity and prediabetes | −12.3% / −18.7% / −19.7% vs −1.3% at 176 weeks |
| STEP 5 | semaglutide 2.4 mg | 304 adults with obesity or overweight | −15.2% vs −2.6% at 104 weeks |
Read together, they say the plateau is real and arrives somewhere after the first year, and that on continued treatment the lower weight largely held — SELECT for four years, SURMOUNT-1 for more than three. The Wegovy label's own table for SELECT at 104 weeks gives −9.4 kg on semaglutide against −0.9 kg on placebo.
SELECT's figure sits below the dedicated weight trials' for reasons the trial itself explains: it was a heart trial without a structured diet programme, and the abstract reports that discontinuation of the drug was higher on semaglutide than on placebo over four years. It is the best evidence that the plateau holds, not a measure of how much weight the drug removes.
The plateau is not the drug stopping
The strongest evidence that a plateau is the drug holding weight down, not failing, comes from the trials that took it away.
- STEP 4: after a 20-week lead-in on Wegovy, people who continued lost a further 7.9% by week 68; people switched to placebo regained 6.9%.
- SURMOUNT-4: after 36 weeks on tirzepatide, people who continued lost a further 5.5% by week 88; people switched to placebo regained 14.0%.
Both show more weight coming off after the escalation phase, then the difference between continuing and stopping. What happens after stopping is set out on our stopping GLP-1 page.
What has been tested at or after a plateau
Three things, and only one trial was designed around people who had actually plateaued.
1. Continuing. As above: in every trial that ran long enough, continuing the drug kept most of the weight off.
2. A higher dose. The Wegovy label now includes a 7.2 mg dose, tested in two 72-week trials:
| Trial (Wegovy label, Studies 8 and 9) | Placebo | 2.4 mg | 7.2 mg |
|---|---|---|---|
| Adults with obesity | −3.9% | −15.5% | −18.8% |
| Adults with type 2 diabetes and obesity | −3.8% | −10.4% | −13.2% |
The higher dose removed about three more percentage points, and brought more side effects, most strikingly skin-sensation reactions in 22% against 6% (see dose and side effects). But those trials started both doses from baseline. They did not enrol people who had plateaued on 2.4 mg and then raise the dose, so they do not directly answer whether a higher dose restarts weight loss after a stall.
3. Switching. ATTAIN-MAINTAIN is the trial that enrolled people at a plateau. Participants from SURMOUNT-5 who had reached a weight plateau on tirzepatide (205) or semaglutide (171) were randomised to once-daily orforglipron or placebo. At week 52 the estimated share of their weight reduction still kept was:
| Coming from | Orforglipron | Placebo |
|---|---|---|
| Tirzepatide | 74.7% | 49.2% |
| Semaglutide | 79.3% | 37.6% |
This tested switching as a way to keep weight off with a pill, not to lose more. The trial had no arm that simply stayed on the injection, lasted one year, and was run by Lilly, which makes orforglipron; its authors list both limitations. The pill itself is covered on our Foundayo vs Wegovy pill page.
Diabetes and the plateau
The curve flattens earlier and lower in people with type 2 diabetes. On the Wegovy label, the same 7.2 mg dose gave −18.8% in adults with obesity and −13.2% in adults who also had diabetes. The tirzepatide labels show the same pattern between the Zepbound and Mounjaro trials, which is one reason the two brands' weight results differ (Mounjaro vs Zepbound).
What the trials do not say
- Why the curve flattens. The trials measure the shape; they do not test the explanation.
- Whether a diet or exercise change breaks a plateau on these drugs. None of the trials above randomised that question.
- What one person's stall means. A stall during dose escalation, a missed dose or a change in another medicine is not the same thing as the late plateau the trials describe. Those are questions for the prescriber.
Sources
- Ryan DH, et al. Long-term weight loss effects of semaglutide in obesity without diabetes in the SELECT trial. Nat Med 2024 — PubMed 38740993.
- Jastreboff AM, et al. Tirzepatide for obesity treatment and diabetes prevention. N Engl J Med 2025 — PubMed 39536238.
- Garvey WT, et al. Two-year effects of semaglutide in adults with overweight or obesity: the STEP 5 trial. Nat Med 2022 — PubMed 36216945.
- Aronne LJ, et al. Continued treatment with tirzepatide for maintenance of weight reduction in adults with obesity (SURMOUNT-4). JAMA 2024 — PubMed 38078870.
- Aronne LJ, et al. Orforglipron for maintenance of body weight reduction: the ATTAIN-MAINTAIN trial. Nat Med 2026 — PubMed 42120723.
- WEGOVY (semaglutide) prescribing information, Novo Nordisk, SPL effective 2026-06-18 — DailyMed, Tables 4, 7, 9 and 12.