Dexatrim, once one of the most popular over-the-counter diet pills in the United States, was pulled from its original formula in November 2000 after the FDA linked its active ingredient to a serious risk of stroke. The ingredient, phenylpropanolamine (PPA), had been used in diet pills and cold medications for decades before safety concerns forced it off shelves.
The Ingredient That Triggered the Removal
PPA was a stimulant that suppressed appetite and also worked as a nasal decongestant. It appeared not just in Dexatrim but in dozens of cold and flu products. In 2000, a large study found that PPA significantly increased the risk of hemorrhagic stroke, particularly in women taking it as an appetite suppressant. The risk was present even at recommended doses.
In November 2000, the FDA requested that all drug companies stop marketing products containing PPA. Most manufacturers, including Dexatrim’s maker Chattem, voluntarily pulled their PPA-based products while the FDA worked through the formal regulatory process to ban the ingredient entirely. PPA has never returned to the U.S. over-the-counter market.
Lawsuits and Financial Fallout
The health consequences of PPA hit Chattem hard in court. In April 2004, the company entered a national class action settlement covering all Dexatrim PPA claims, with approximately $70.9 million initially funded into a settlement trust. A federal judge in Washington state certified the class and approved the settlement in November 2004.
Beyond the class action, Chattem faced individual lawsuits from people who developed pulmonary arterial hypertension, a dangerous condition where blood pressure in the lungs becomes dangerously high, after taking Dexatrim between 1998 and 2003. In 2008, the company settled all 26 known claims for $13.3 million, with about $2.5 million offset by remaining funds in the litigation trust. Combined with legal fees, the total cost of PPA-related litigation ran well into the tens of millions.
Dexatrim’s Reformulations
Rather than disappear entirely, the Dexatrim brand went through multiple reformulations. After PPA was removed, some weight loss supplements shifted to ephedra, a plant-based stimulant with similar appetite-suppressing effects. The FDA banned ephedra-containing dietary supplements in 2004 after linking them to heart attacks, strokes, and deaths, closing off that path as well.
Later versions of Dexatrim used ingredients like bitter orange extract, which contains a compound called synephrine. Synephrine is structurally similar to both ephedrine and adrenaline, which is why it raises some of the same safety flags. Health Canada has capped the recommended daily intake of synephrine at 30 mg and warns against combining it with caffeine, as the combination may increase cardiovascular side effects. People with high blood pressure, heart disease, or diabetes are advised to avoid it. Even in healthy adults, regulatory guidelines suggest not using synephrine-containing products for longer than eight weeks due to limited long-term safety data.
These reformulated products never came close to matching the original Dexatrim’s popularity or market presence. The brand name still surfaces occasionally on supplement shelves, but it bears little resemblance to the product that millions of Americans used in the 1980s and 1990s.
Why PPA Stayed on the Market So Long
PPA had been available without a prescription since the 1930s, and for most of that time, it was considered safe at recommended doses. The FDA’s over-the-counter drug review process, which evaluates whether ingredients are “generally recognized as safe and effective,” moved slowly. Early warning signs about PPA’s cardiovascular risks appeared in case reports through the 1980s and 1990s, but it took a controlled study large enough to quantify the stroke risk before the FDA acted. Once that evidence arrived, the agency moved quickly, issuing its public health advisory and requesting voluntary removal within weeks.
The Dexatrim story is a case study in how an ingredient widely assumed to be safe can remain on the market for decades before the right kind of evidence surfaces. PPA was in hundreds of products used by millions of people. The 2000 removal affected not just diet pills but a significant portion of the cold and flu medication aisle, forcing widespread reformulation across the pharmaceutical industry.