Diet pills and sexual enhancement products sold over-the-counter as “all natural” herbal supplements may contain dangerous, hidden drugs and could cause more harm than good, according to a study conducted by researchers with Queen’s University Belfast, Kingston University London, and LGC, an international life sciences testing company.
Analyses found that many dietary supplements promoted for weight loss contain the stimulant sibutramine, but don’t list the drug as an ingredient on the product’s label. Sibutramine was a prescription weight loss product that was banned years ago in both the U.S. and U.K. after its was linked to heart attacks and strokes.
“Customers… are being deceived into thinking they are getting health benefits from a natural product when actually they are taking a hidden drug,” said Emeritus Professor Duncan Burns, an analytical chemist from Queen’s University Belfast’s Institute for Global Food Security. He is also author of the study.
Laboratory analyses also found that herbal supplements for sexual enhancement or erectile dysfunction (ED) contained tadalfil, the active ingredient in the ED drug Cialis, and sulfoaildenafil, a derivative of the ED drug Viagra, which is not sold in the U.S. The drugs can interact with nitrates, leading to dangerously low blood pressure and related consequences.
“These products are unlicensed medicines and many people are consuming large quantities without knowing the interactions with other supplements or medicines they may be taking,” Burns said. “This is very dangerous and there can be severe side effects.”
In recent years, the U.S. Food and Drug Administration (FDA) has cracked down on manufacturers and marketers of dietary supplements that contain dangerous, hidden ingredients. However, the FDA has no jurisdiction over the approval of these products and only conducts analyses if there is a reason to do so. The agency recommends consumers be wary of supplements promoted for weight loss and sexual enhancement, as well as athletic performance or bodybuilding, as these are most likely to contain hidden drugs.