The Food and Drug Administration has approved a new prescription weight loss pill called Contrave for sale in the U.S., making it one of only four prescription obesity drugs recognized by the FDA and the third since 2012. The FDA green-lighted the first such pill in 1999.

With obesity rates in the U.S. at an all-time high, health officials say there is an urgent need for noninvasive approaches to weight loss in addition to exercise and dieting, but experts wonder if the few FDA-approved weight loss pills that are available, including Contrave, will appeal to consumers. Few health insurers cover obesity pills, according to Reuters, in part because they remain skeptical of the drugs’ long-term effectiveness. 

Another problem is that many doctors and obese people do not consider medicine as a way to treat obesity, according to the New York Times. Also, any weight loss experienced from prescription diet pills is usually modest.

The prescription weight loss drug Belviq was approved by federal regulators in June 2012. A second obesity drug, Qsymia, was approved less than a month later. Both have had disappointing sales since going on the market, in part because of failed marketing strategies, analysts say.

However, some experts predict that Contrave, which is manufactured by San Diego-based Orexigen Therapeutics and will be marketed by Takeda Pharmaceutical of Japan, has the potential to outpace its predecessors. "If these obesity cardiovascular outcomes trials do show that they reduce heart attacks, or hospitalizations, then ... the market would be reignited," Daniel Lang, a trained cardiologist, told Reuters.

Contrave is a combination of two FDA-approved drugs, the antidepressant bupropion and naltrexone, which is used to treat drug dependence. It has been approved for use in adults whose body mass index is 30 or greater or for adults whose body mass index is 27 or greater but who have at least one weight-related condition such as hypertension or Type 2 diabetes, according to a statement from the FDA.

Because the pill contains an antidepressant, the FDA requires it carry a warning about increased risk of suicidal thoughts and behaviors. The company did not say when Contrave would be available or what the price would be.

In a clinical trial, those who took Contrave lost an average of 4.1 percent more weight than those who received placebos. Over 40 percent of the patients who received the drug lost at least 5 percent of their weight compared with 17 percent of those taking placebos, according to the FDA.

“Obesity continues to be a major public health concern,” Jean-Marc Guettier, director of the Division of Metabolism and Endocrinology Products in the FDA’s Center for Drug Evaluation and Research, said in a statement. “When used as directed in combination with a healthy lifestyle that includes a reduced-calorie diet and exercise, Contrave provides another treatment option for chronic weight management for people who are obese or are overweight and have at least one weight-related health condition.”