What to Know About Zepbound, the New Weight Loss Drug

The decision by the Food and Drug Administration on Wednesday to approve the weight loss drug tirzepatide adds a potent new tool to the fast-growing arsenal of obesity drugs.

The drug, which will go by the brand name Zepbound, contains the same compound in the sought-after diabetes drug Mounjaro. Many people have used Mounjaro off-label to lose weight since it was initially approved in May 2022, but the move could pave the way for insurance coverage and open the floodgates for more prescriptions.

Zepbound is the second drug in a new class of obesity medications to be approved for weight loss, following Wegovy. And it is now likely the most effective treatment to combat obesity besides bariatric surgery, said Dr. Scott Hagan, an assistant professor of medicine at the University of Washington. But for many, Mounjaro has been hard to find in the year since it hit the market.

“It’s very similar to what we went through with Ozempic,” said Dr. Andrew Kraftson, a clinical associate professor in the division of metabolism, endocrinology and diabetes at Michigan Medicine, noting that demand for weight loss medications has hit a “fever pitch.” Now, he said, patients will likely be clamoring for this new drug. Here’s what to know.

Who qualifies for Zepbound?

The F.D.A. approved Zepbound for people who have a body mass index — a much-criticized metric — of 30 or greater, which technically qualifies them as having obesity, or those with a B.M.I. of 27 who also have certain weight-related conditions, such as high blood pressure. Regulators said the drug should be used in combination with a reduced calorie diet and increased physical activity.

How does tirzepatide work for weight loss?

Zepbound, made by Eli Lilly, is the brand name for tirzepatide when used for weight loss. When the drug is prescribed for diabetes, it is sold under the brand name Mounjaro.