They Thought Ozempic Would Help Them Lose Weight. It Didn’t Work.

Behind the blockbuster success of drugs like Ozempic and Wegovy is a less-noticed phenomenon: Some people don’t lose much weight on them.

There is wide variation in weight loss on these types of drugs, called GLP-1s. Doctors say roughly 10% to 15% of people who try them are “non-responders,” typically defined as those who lose less than 5% of their body weight. These patients, doctors say, don’t experience enough appetite reduction to result in significant weight loss.

Researchers are studying why some people drop a lot of weight on them while others lose little. The answers might yield broader clues about weight loss and provide more insight into these medications, which have transformed the way Americans lose weight.

Doctors believe some people might be resistant to the drugs as a result of genetic differences. Other possible reasons could include certain medical conditions and medications, how much weight a person lost before taking the drugs, and differences in how people metabolize them.