GLP-1 weight loss drugs – friend or foe?
The real question is whether these drugs leave you better or worse off long term (say, over 5 years). The best answer comes from looking at all the trials on weight loss using GLP-1s versus solid behavioural approaches.
A major new systematic review just out in the BMJ sums up 37 studies on what happens when people stop these meds.
Key facts:
– You lose more weight upfront with GLP-1 drugs than with behavioural methods alone (often 10-15 kg vs less).
– Everyone regains eventually.
– Stop the GLP-1s and, on average, you end up back where you started – or even heavier – within about 1.5-2 years. Regain happens fast (around 0.4 kg/month overall, quicker with the newer ones like semaglutide/tirzepatide at ~0.8 kg/month).
– Muscle loss is a real issue too, as these drugs can hit lean mass hard.
With behavioural weight loss alone, there’s typically modest weight still kept off after 5 years.
Bottom line: these drugs overpromise and can make medium-term weight gain worse if you stop (which half of people do within a year in real-world data).
They deliver big short-term wins, no question. But, in my opinion, behavioural medicine is the future of medicine.
Would you take them? Have you taken them? What have you seen in practice? Let’s hear it.
Full paper here: https://www.bmj.com/content/392/bmj-2025-085304
