A shocking 20% of supplements tested by the Food and Drug Administration was found to contain prescription medications that had no business being included.
But the agency is responsible for testing any suspicious products and issuing recalls if they contain any mislabeled, potentially risky or unapproved ingredients.
In a report published on JAMA Network Open, the authors explain that potentially harmful active drugs continue to be identified by the FDA in over-the-counter dietary supplements.
Though the FDA "has other enforcement tools at its disposal", the new study is consistent with previous research showing "major deficiencies in the FDA's regulation of supplements", wrote Cohen, who was not involved in this study.
The most common drugs found in supplements were sildenafil (the active ingredient in Viagra) for sex supplements, sibutramine (a banned weight-loss drug) for weight-loss supplements, and synthetic steroids or steroid-like ingredients for muscle-building supplements, the researchers said.
Of the adulterated products, almost 46 percent were for sexual performance, 41 percent were for weight loss and 12 percent were for building muscle.
This study analyzed data from a tainted supplements database maintained by the FDA for trends in adulterated dietary supplements associated with a warning by the FDA.
In a commentary accompanying the article, Harvard Medical School professor and general internist Dr. Pieter A. Cohen chastised the FDA for a "dereliction of duty" as the agency responsible for regulating and ensuring the safety of consumer dietary supplements such as vitamins, minerals, probiotics, amino acids, and enzymes. He suggested that companies be required to register the products with the FDA before sale.
When a company refuses to voluntarily recall its products, the FDA has a number of tools it can use to get the product off the market: the agency can send a warning letter to the company, visit the factory for an inspection or issue a mandatory recall.
"There's just no way to interpret this other than the FDA is simply not doing its job", Cohen said. Additionally, patients who take prescription medications already and then add a supplement without their doctor's knowledge could be at risk of drug interactions without even knowing it. Sibutramine, widely found in the weight loss products, can substantially increase blood pressure and pulse rate. If a supplement is deemed a health risk, then the agency can issue a class action recall; however, this is hard to prove and often goes underreported.
A 2015 study found that dietary supplements are tied to 23,000 emergency room visits and 2,000 hospitalizations in the USA each year. If the company refuses to recall the product, the agency should follow up with aggressive actions to make sure the product is not available to consumers. That way, each supplement would have a registration code to identify it, which would allow the FDA to know exactly what supplements are being sold in the country.
These categories of supplements are particularly prone to having manufacturers use pharmaceutical ingredients because 'these three categories have pharmaceutical drugs that can help with these things, ' Dr Cohen says.
But in the meantime, there are steps consumers can take to protect themselves from tainted supplements.
Men precluded from taking erectile dysfunction drugs may turn to these supplements, not realizing that they are getting the very same pharmaceuticals, they said.