Obesity drugs cut weight but do not improve quality of life, study finds

A comprehensive analysis published in the BMJ examined 262 randomized trials involving 99,791 adults with overweight or obesity. The review compared 19 injectable or oral drugs, including tirzepatide (Mounjaro/Zepbound), semaglutide (Wegovy/Ozempic), and the experimental combo CagriSema. Over a 12‑to‑172‑week follow‑up, the greatest average weight loss after one year was seen with tirzepatide (14.9 %) and CagriSema (14.8 %).

Despite the substantial weight loss, most drugs did not produce clinically meaningful improvements in health‑related quality of life. Only semaglutide injections showed a clear reduction in all‑cause mortality (19 %), heart attack (28 %) and heart‑failure risk (57 %). Greater weight loss consistently coincided with higher rates of gastrointestinal side‑effects, fatigue and loss of lean muscle mass.

The authors note that trial follow‑up periods were relatively short, limiting understanding of long‑term safety, kidney outcomes and sustained quality‑of‑life benefits. Parallel real‑world research from a wearable‑tech firm in the United States observed a modest rise in resting heart rate and a drop in heart‑rate variability among GLP‑1 users, suggesting potential cardiovascular strain that may be mitigated by regular physical activity.

Overall, the findings underscore that while obesity pharmacotherapy can deliver notable weight reductions, clinicians and patients must weigh these gains against adverse effects and the lack of proven quality‑of‑life or broad cardiovascular advantages.