The group of outside physicians voted 20-2 in favor of the weight-loss drug Qnexa.
Qnexa is a combination of two existing drugs: the appetite suppressant phentermine and the anti-seizure medication topiramate. It may be the first new prescription diet pill on the market in 13 years.
"If approved, Qnexa would be the most potent medicine we would have on the market to treat obesity. The currently available drugs are not very effective," said Dr. Tim Garvey of the University of Alabama at Birmingham.
The panel's support sets the stage for a potential comeback for the drug that has been plagued by side effects since it was first submitted to the agency in 2010.
A majority of panelists ultimately backed the drug due to its impressive weight loss results, but not all doctors are convinced it's a safe option. Potential side effects are serious. They include increased heart rate, kidney stones, memory loss and birth defects. There's also some concern about whether Qnexa is linked to an increased risk of heart attack and stroke.
The drug works by making patients feel full. It has already helped 20-year-old Frazier Harzell lose 165 pounds in just one year.
"I went from 390 pounds to 225 pounds. It definitely changed my life," Harzell said.
The group stressed that the drugmaker must be required to conduct a large, follow-up study of the pill's effects on the heart.
"The potential benefits of this medication seem to trump the side effects, but in truth, only time will tell," said Dr. Kenneth Burman of the Washington Hospital Center.
The FDA's final decision on the drug is expected by mid-April.
The Associated Press contributed to this report.