A Diet-Pill ‘Miracle’ That Wasn’t
Long before the weight-loss medications of today, the rage for fen-phen turned into a tragedy.
March 26, 2025
In 1979, a professor of clinical pharmacology at the University of Rochester made a curiously potent discovery. He took two underperforming diet drugs, fenfluramine and phentermine, and decided that perhaps combining them would work as a powerful elixir in treating obesity. And indeed, his fen-phen cocktail helped 121 obese patients lose significant weight over four years, prompting him to publish a paper in 1992 extolling its virtues. Both drugs had received FDA approval, so there was nothing to stop the two-pill regimen from hitting the market.
And it did—big-time—with overweight consumers seeking a magical weight-loss solution going wild with demand. “Even in a nation obsessed with weight loss, there’s never been anything quite like fen-phen,” wrote The American Lawyer in 2005. American Home Products, a large drug company, marketed the appetite suppressants called Redux and Pondimin, along with phentermine, as part of the fen-phen offerings. Patients didn’t even have to exercise in order to shed pounds; this was a miracle pill indeed. “No pain, and no gain,” was the not-so-subtle message.
But while it may be long forgotten today, fen-phen would become a great medical debacle. It turned out the two drugs used together caused heart-valve damage and primary pulmonary hypertension. Users, mostly women, began to experience serious medical problems, and in 1997, the FDA ordered American Home Products to pull the drugs off the market.
But the damage had been done. Over six million prescriptions had been written in the relatively short time fen-phen was on the market, and when word got out about its dangers, a litigation frenzy commenced. A tidal wave of lawsuits was filed, at one point reaching an estimated 175,000 claims against American Home Products. Against such an onslaught, the company would agree to a $3.75 billion class-action settlement within two years. At the time, it was one of the largest such settlements for product liability in corporate history. Still, the lawsuits kept coming.
The search for that magic pill, of course, has never ended, as demonstrated by the surge in popularity of Ozempic, the current diet-pill darling. But experts say the lessons of fen-phen should be clear. The diet doctors back then were practicing “witchcraft,” Dr. Richard A. Friedman told The New York Times in 1997. Then director of the psychopharmacology clinic at New York-Cornell Medical Center, Dr. Friedman warned that clinical drug trials had to be far longer than the year fen-phen was assessed. “Physicians, of all people,” he said, “might be expected to be skeptical and respect the powerful effects of drugs.”
Photo Credits: Science Source / Scott Camazine; Yvonne Hemsey
