Which Weight Loss Drug Should You Choose (if You Get to Choose)?

People with obesity now have a choice between two powerful drugs to help them lose weight. One is semaglutide, sold by Novo Nordisk as Wegovy for obesity treatment and as Ozempic for diabetes. The second, tirzepatide, is sold by Eli Lilly as Zepbound for obesity and as Mounjaro for diabetes. Many with neither obesity or diabetes take the drugs to get thinner.

A recent study suggested that people lost more weight taking Mounjaro than they did taking Ozempic, and it may leave you wondering: Which should I take? And if I’m already taking one of them, should I switch?

The answers, obesity medicine experts say, are not so simple. Here are some factors that can help sort out hype from realistic hope.

Is one weight loss drug really better than the other?

For now, it’s hard to say. All of the information available comes from “highly flawed studies,” said Dr. Diana Thiara, medical director of the weight loss clinic at the University of California, San Francisco.

That includes the recent study comparing Mounjaro and Ozempic. Using electronic health records, the researchers reported that those taking Mounjaro lost an average of 15.3 percent of their weight after a year. Those taking Ozempic lost an average of 8.3 percent.

While that sounds impressive, Dr. Susan Z. Yanovski, co-director of the Office of Obesity Research at the National Institute of Diabetes and Digestive and Kidney Diseases, said, “I wouldn’t make any decisions on my medical care based solely on a study like this.”