US health regulators have approved weight-loss pill Belviq, marking the first new drug treatment in 13 years.

Belviq (lorcaserin hydrochloride), made by Arena Pharmaceutical, can be used by obese or overweight adults with at least one condition.

The drug achieved only modest results in clinical studies, helping people lose on average about 5% of their body weight.

Belviq was rejected in 2010 because of concerns over tumors that developed in animals tested with the drug.

After San Diego-based Arena resubmitted its application with more data, the US Food and Drug Administration (FDA) found little risk of tumors in humans using the drug.

FDA approved weight-loss pill Belviq, marking the first new drug treatment in 13 years

The medication is expected to launch in 2013.

Belviq is designed to block appetite signals in the brain, making patients feel fuller with smaller amounts of food.

Belviq is a serotonin 2C receptor agonist indicated as an adjunct to a reduced-calorie diet and increased physical activity for chronic weight management in adults with an initial body mass index (BMI) of 30 kg/m2 or greater (obese) or 27 kg/m2 or greater (overweight) in the presence of at least one weight-related comorbid condition, (e.g., hypertension, dyslipidemia, type 2 diabetes).

The FDA warned that Belviq is not for women who are pregnant or nursing.

With US obesity rates approaching 35% in adults and associated healthcare costs on the rise, many doctors have urged health regulators to give the green light to new weight-loss treatments.

But the agency has set high standards for such medication after safety problems with previously popular weight-loss drugs.

The so-called fen-phen combination had to be pulled from the market in 1997 after being linked to heart valve damage.

In a statement, the FDA said Belviq did not appear to carry the same risks.

However, known side effects of Belviq do include depression, migraine and memory lapses.

The FDA-approved label says the drug should not be used for more than 12 weeks if a 5% weight loss does not occur.

Arena will be required to conduct six studies after marketing the drug, including a study on the drug’s effect on long-term heart health.