The Food and Drug Administration (FDA) issued a warning this week about a batch of popular diet pills and supplements, including Fat Zero, NBC News reports. While many diet products claim to be all natural and include ingredients such as bee pollen and green tea, all of the brands that the FDA is issuing warnings about also include sibutramine, which has been shown to cause heart problems, and phenolphthalein, which has been linked to cancer.
“Sibutramine is a controlled substance that was removed from the market in October 2010 for safety reasons,” the FDA said in an official statement. “The product poses a threat to consumers because sibutramine is known to substantially increase blood pressure and/or pulse rate in some patients and may present a significant risk for patients with a history of coronary artery disease, congestive heart failure, arrhythmias, or stroke. This product may also interact, in life-threatening ways, with other medications a consumer may be taking.”
The FDA is also targeting other products that include vardenafil, the active ingredient in Viagra. Often found in supplements that are designed to enhance your sex life, vardenafil can interact with nitrates found in some prescription drugs.
“This undeclared ingredient may interact with nitrates found in some prescription drugs, such as nitroglycerin, and may lower blood pressure to dangerous levels,” FDA cautions. “Consumers should stop using this product immediately and throw it away. Consumers who have experienced any negative side effects should consult a health care professional as soon as possible.”
As long as supplements and herbal products don't make specific health claims, they don't require FDA approval to include ingredients that are "generally recognized as safe" (GRAS). However, the FDA can and does periodically test these products and if it finds that they're using dangerous products, it can warn the public.