There's another pill to help people lose weight.

After years of study and lots of questions from the Food and Drug Administration questions, a pill called Contrave finally got the agency's OK Thursday.

It's the third diet medicine to get the regulatory go-ahead in recent years. But the other drugs — Qsymia and Belviq — haven't proved that popular. Many insurers have been reluctant to cover the medicines.

Contrave, for better or worse, is a combination of two drugs that have been around for a long time. One is bupropion, an antidepressant sold as Wellbutrin, that's also been used to help people stop smoking. The other is naltrexone, a medicine that's prescribed to help people stay off drugs and alcohol.

Contrave is intended for people who are obese or who are overweight and have other weight-related health problems, such as high blood pressure and type 2 diabetes.

In a study of people without diabetes, 42 percent of patients who got Contrave lost at least 5 percent of their weight over about a year compared with 17 percent for those who took a placebo. A study in people with diabetes found that 36 percent received Contrave lost at least 5 percent of their weight compared with 18 percent who got a placebo. (You can find the study details in the instructions to doctors who might consider prescribing the drug.)

People in the studies also reduced the calories they consumed and exercised. In one study the patients also got counseling about weight loss. Contrave is supposed to be used in combination with other weight-loss approaches.

Contrave has side effects. The most common ones include nausea, constipation and headache. About a quarter of people taking the drugs in clinical tests stopped taking the drug because of side effects.

Contrave also comes with a stern warning about the potential for suicidal thoughts and behavior, which is consistent with the instructions for Wellbutrin.

All told, almost half of people taking Contrave or the placebo used for comparison stopped taking their pills before the studies were finished. The FDA says people who haven't lost at least 5 percent of their weight after taking Contrave for 12 weeks should stop the medicine because it's unlikely to help them.

Back in 2011, the FDA rejected the Contrave application, despite a recommendation for approval from an outside panel of experts. The agency was concerned, among other things, about potential heart risks. Orexigen Therapeutics, developer of the drug, agreed to run a study looking at cardiovascular risks.

The interim results apparently were reassuring enough for the FDA to approve Contrave. But the company hasn't released the data. Orexigen and Takeda agreed to conduct a new study looking at heart risks as a condition for approval of the drug.

Contrave will be available in pharmacies this fall, according to Takeda Pharmaceuticals and Orexigen, the companies working on the drug's marketing.

How much will it cost? The companies won't say yet. "For price, it's not Takeda's policy to disclose," spokesman Bob Skinner told me in an email. He said Takeda will offer a savings program to make the medicine more affordable for people whose insurance won't cover the medicine.

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