How much weight can you lose?
In large registration studies, participants lost on average about 15% of their body weight with semaglutide and up to about 20% with tirzepatide, each in combination with lifestyle advice. These are study averages and not a promise: the actual result varies greatly from person to person. GLP-1 medication is prescription-only; a doctor assesses whether it is suitable for you and discusses realistic expectations.
What do the studies show?
The figures below come from large clinical registration studies and are averages across the whole study group. They give an indication, not a prediction for the individual.
| Active substance | Study (indicative) | Average weight loss | Duration |
|---|---|---|---|
| Semaglutide | STEP 1 | ± 15% of body weight | ± 68 weeks |
| Tirzepatide | SURMOUNT-1 | ± 20% (highest dose) | ± 72 weeks |
In the same studies, the medication was always combined with changes to nutrition and exercise. The medication supports the process, but lifestyle remains an important factor.
Why does the result differ from person to person?
Weight loss depends on many factors, including:
- starting weight and body composition;
- the dose and how well you tolerate it;
- nutrition, exercise and sleep;
- how long you keep up the treatment;
- underlying conditions and other medication.
Some people lose more than the average, others less. A proportion respond only modestly to the medication. That is why medical guidance is important.
No guarantee and no miracle pill
GLP-1 medication is not a miracle cure and does not give a guaranteed result. The effects seen in studies were achieved under guidance and with lifestyle changes. Those who stop the medication often see (some of) the weight return, unless lifestyle changes are kept up.
Frequently asked questions
How many kilos will I lose with Ozempic or Mounjaro?
Do you lose weight faster with tirzepatide than with semaglutide?
Will I keep the weight off?
Official sources on this topic
Independent, authoritative information from official bodies: