U.S.— A total of 776 over-the-counter dietary supplements were found to contain potentially harmful drugs.
According to a study published in JAMA Network Open, 97.6 percent of the ingredients present in supplements were not labeled on the products.
Eighty-six percent of the contaminated drugs were mainly found in supplements labeled as drugs for weight loss and sexual enhancement, while 12 percent were found in muscle building supplements.
One in five supplements were found to contain more than one pharmaceutical drug.
Sildenafil, the active ingredient for Viagra, was the most common drug found in sexual enhancement supplements while sibutramine, a weight-loss drug banned by the FDA, was found in weight loss supplements.
Dr. Louis Aronne, a professor of metabolic research, told Reuters that dietary supplements are hard to regulate as they are often sold and marketed online.
Less than half of the contaminated supplements were ever recalled from stores, according to Scientific American.
The FDA can issue a warning and ask the company to voluntarily recall their products, however the FDA can't force the companies to do so as dietary supplements aren't regulated like other medication, according to Forbes.