Three trials deliberately took people off these drugs and kept weighing them. Across all three, roughly two-thirds of the lost weight returned within a year. Here is what that arithmetic looks like on your numbers.
| 3 months after stopping | — |
|---|---|
| 6 months after stopping | — |
| 12 months after stopping | — |
| 12 months if you stayed on instead | — |
| Difference at 12 months | — |
In the STEP 1 extension, participants who had lost about 17% of their body weight on semaglutide came off the drug and were followed for another year. A year later they had regained roughly two-thirds of it, sitting about 6% below where they had started. STEP 4 ran the cleaner version of the experiment: everyone got the drug for 20 weeks, then half were switched to placebo. Over the next 48 weeks the placebo group gained about 7% while the group that stayed on lost a further 8%.
SURMOUNT-4 did the same with tirzepatide. After 36 weeks the group averaged about 21% below baseline; the half switched to placebo regained about 14 percentage points over the next year, while the half who continued lost another 5 or so.
All three trials point the same way and the arithmetic is the same for every drug in this class: these medications treat the condition while they are being taken. Stopping is not a graduation.
They do not tell you that regain is inevitable for you specifically. The trial participants who came off had no structured maintenance programme; they simply stopped and were measured. Longer-running observational work on people who have maintained large losses without drugs — the National Weight Control Registry being the best known — consistently finds high physical activity, regular self-weighing and consistent eating patterns among those who hold their loss. That is association rather than proof, and none of those studies were done in people coming off a GLP-1.
What is fair to say: the regain figures above describe stopping with nothing in place. They are a reasonable default expectation, not a sentence.
They also cannot tell you what a lower dose would do, and this page deliberately does not model that. Dose is a decision for the person who wrote your prescription.