Phen-Fen, a blockbuster diet drug pulled off the market a decade ago amid reports of heart valve problems, could be making a comeback.
The prescription drug arrived in the early 1990's and proved to be the most potent appetite suppressant ever to hit the market.
"It was so successful at inducing weight loss that clinics rose up around the country solely devoted to prescribing Phen-Fen," explained the University of North Carolina's Dr. Bryan Roth.
That success seemed too good to be true.
Heart valve problems appeared in some patients, leading the FDA to pull the diet drug cocktail.
Drug maker Wyeth faced legal claims that would total billions, and said it had no plans to bring the drug back to market.
It seemed the Phen-Fen run was over.
Dr. Roth and his team at the University of North Carolina may change that.
Roth has one of the few labs around the country that analyzes drug side effects, and was the first to tackle the mechanism behind Phen-Fen's dangerous heart effects.
"It was a serotonin receptor, it was found specifically in the heart," he explained.
The discovery that has been confirmed, resurrecting the possibility of the return of Phen-Fen.
"You could make drug that targets basically the healthy, or magic receptor for weight gain and misses the receptor for side effects," said Dr. Roth.
A number of companies are racing to do just that.
One drug is now being tested in people.
Despite the fall of drugs like Phen-Fen, the diet drug business is still booming.