Thus consumers tend to learn of safety and quality issues only after supplements are on the market. In August, for instance, the FDA warned people not to take red yeast rice supplements sold by Swanson Healthcare Products Inc. or Sunburst Biorganics because they contained lovastatin, a prescription drug used to treat high cholesterol. And in September, the agency recalled Axcil and Desirin, herbal supplements made by twc Global of Mountain View, Calif., because the pills contained sildenafil, the active ingredient in Viagra. That drug can interact with nitrates taken for heart problems and may dangerously lower blood pressure.
In September, new ConsumerLab.com tests found that three of the 10 tested B-vitamin supplements had less folic acid than claimed. That may be because folic acid degrades if it's not stored properly, says President Tod Cooperman. Supplement purchasers concerned about quality and safety should be particularly careful about herbals, he says, because they are more likely to be of poor quality or contaminated. He suggests checking out independent laboratories that test supplements, including US Pharmacopeia and his company, ConsumerLab.com, which charges $29.95 a year for access to test data. Simplest of all, buy two different brands of multivitamins and switch daily. That way, he says, if one is subpar, at least the other may measure up.