Drugmaker Eli Lilly said that in Phase 3 studies of over 550 adults, their oral GLP-1 pill, orforglipron, could reduce hemoglobin A1C levels on average by 1.3-1.6% and also help people lose up to 16 pounds, or about 7.9% of their body weight.

But this one, for Lilly’s first diabetes and weight-loss pill based on the GLP-1 hormone, was particularly fraught. Days before, rival pharma giant Pfizer had announced it was abandoning its oral weight-loss drug after worrying side effects involving liver problems were reported in one participant in the trial.

Medical conditions can limit which weight loss pills work safely for you. For example, you should avoid phentermine if you have severe anxiety or hyperthyroidism. Nadler emphasizes the importance of taking anti-obesity medication only under the supervision of a health care professional.