How much weight can you actually expect to lose?

It is the first question almost everyone asks, and it deserves an honest answer rather than a marketing one. The truth is that the trial numbers are genuinely striking — and that an average is a poor predictor of any single person’s result.

What the trials showed

In STEP 1, adults with overweight or obesity taking weekly semaglutide 2.4 mg alongside lifestyle support lost about 15% of their body weight on average over 68 weeks, compared with roughly 2–3% on placebo plus the same support. In SURMOUNT-1, tirzepatide produced average reductions of up to around 21% at the highest dose over 72 weeks. Liraglutide, an earlier daily GLP-1, showed more modest average loss in the SCALE trial.

Why “average” hides the real story

Those headline figures are means. Underneath them is a wide spread: some people lose far more, some considerably less, and a minority respond only modestly. Your starting weight, biology, the specific medicine and dose, and — crucially — the nutrition and activity changes alongside it all move your individual result.

The trajectory matters

Weight loss on GLP-1 therapy is gradual and dose-dependent. Doses are titrated upward slowly over weeks to manage side effects, so early weeks are about tolerability, not the scale. Clinicians typically review progress around 8–12 weeks before drawing any conclusions.

A healthier frame than a number

Much of the benefit in the trials came not only from the scale but from what moved with it — blood pressure, blood sugar and waist circumference. Setting a realistic, health-first goal with your physician tends to serve you better than fixating on a target weight. Results vary, and we do not promise a specific outcome.