The U.S. Food and Drug Administration (FDA) has approved a new weight loss pill. Known as Contrave, the drug is said to be effective when used in conjunction with exercise and healthy eating.

People eligible to take the drug are adults with BMIs of at least 30, which is considered obese. Adults with BMIs 27 or higher would be classified overweight but could qualify for the drug if they are also diagnosed with at least one weight related illness such as high blood pressure or cholesterol or type 2 diabetes.

There are two active drugs that comprise the pill. One is called naltrexone, which is a drug used in addiction treatment for dependency of opiods or alcohol. The other drug is named bupropion, which is used to treat depression and to aid in smoking cessation.

Essentially, the new drug is used to help treat food addictions as part of a comprehensive approach to sustained weight loss, researchers say.

Clinical trials involving over 4,500 participants of varying weights have demonstrated the drugs efficacy. After one year of treatment, participants who took Contrave demonstrated an average weight loss of 4.1 percent higher than placebo groups.

Two separate trials revealed higher numbers of people who took Contrave lost at least 5 percent of their body weight at the one year mark. In one trial it was found that 36 percent of those taking the drug lost five percent of their body weight as compared to the placebo groups who saw only 18 percent lose five percent of their weight. A second study found the same amount of weight loss in 42 percent of those taking the pill and only 17 percent of the placebo group able to make the same claims.

There are some potential side effects to the drug. The burpopion contained in the pill comes with a warning of suicidal thoughts and behaviors typical to antidepressants. Other side effects include headache, nausea, vomiting, dizziness, diarrhea or constipation, dry mouth and insomnia.

Doctors recommend that patients stop taking the pill after a trial period of 12 weeks if the person has not lost five percent of their body weight. Experts say that this indicates that the drug is not a useful option for that particular patient.