The US Food and Drug Administration (FDA) have approved a weight-loss pill for the first time in 13 years.
The pill called Belviq, manufactured 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 percent of their body weight.
The FDA had rejected Belviq in 2010 because of concerns over tumours that developed in animals tested with the drug.
After San Diego-based Arena resubmitted its application with more data, FDA found little risk of tumours in humans using the drug.
The medicine is expected to be launched in 2013.
Belviq is designed to block appetite signals in the brain, making patients feel fuller by consuming only a small proportion of food, the BBC reported.
It has been approved for use in obese adults who have a body mass index of 30 or greater.
Overweight adults with a BMI of 27 or greater can also use the drug but they should have at least one other condition such as high blood pressure, type 2 diabetes or high cholesterol.
The FDA warned that Belviq is not for women who are pregnant or nursing.
In America obesity is becoming an epidemic of mass proportions with obesity rates approaching 35 percent in adults and associated healthcare costs on the rise, many doctors had 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 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 that the drug should not be used for more than 12 weeks if a 5 percent 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.