Consumers should not buy sexual enhancement supplements, either online or in stores, because the products may contain undisclosed drugs that could cause serious harm, medical experts say.
Although advertisements on sex supplements purport that the products improve sexual function, there is no evidence to support these claims, said Dr. Pieter Cohen, an assistant professor of medicine at Harvard Medical School and a general internist at Cambridge Health Alliance in Boston. In fact, there is no non-prescription product that has any proven benefit for helping with erections, Cohen said.
Oftentimes manufacturers secretly add prescription drugs, such as sildenafil (sold under the brand name Viagra) or tadalafil (brand name Cialis), so that customers continue to use the products, Cohen said. Sometimes these undisclosed drugs are slightly modified versions of existing drugs, which are completely experimental and have not been shown to be safe, Cohen said.
"These products either do not work, or if they do work, are potentially harmful," because they contain undisclosed drugs, Cohen said.
In 2009, sex supplements tainted with high doses of diabetes medication caused more than 12 deaths in Asia. If doctors, lawmakers and legislatures don't act soon to reduce exposure to these supplements, more deaths could follow, Cohen said.
Doctors should have a low threshold for prescribing erectile dysfunction drugs so that patients do not turn to potentially dangerous supplements, Cohen said.
Sex supplement dangers
The Food and Drug Administration regulates dietary supplements only after they enter the market, and the agency is not able to test all of these products for safety.
Earlier this year, the FDA warned consumers that a number of sexual enhancement supplements contained undisclosed drugs. And a few weeks ago, several sex supplements were recalled.
Consumers who ingest tainted supplements don't know that they are taking prescription drugs, and have not been are not properly counseled about the side effects of the drugs, Cohen said.
What's more, tadalafil and sildenafil can cause adverse effects, including dangerously low blood pressure, if taken along with other prescription drugs that contain nitrates, the FDA says. (Some drugs prescribed to treat chest pain and heart disease contain nitrates.) Patients who can't take erectile dysfunction drugs because of their side effects would unknowingly put themselves at risk by taking sex supplements.
Manufacturers of sex supplements are also increasingly adding modified versions of prescription drugs to their products. So-called "analogues" are almost identical to drugs like sildenafil, but have a slightly different structure, which makes them harder to detect. Today, there are more than 45 different analogues for PDE-5 inhibitor (the class of drugs used to treat erectile dysfunction). Analogues pose "profound" risks to consumers because they are, in essence, new drugs that have unknown side effects, Cohen said.
Legislators should revise the law so that dietary supplement manufactures aren't allowed to make claims like "will improve sex function" on their products without proof, Cohen said.
Regulators should work together to create a database of known analogues so that such experimental drugs are quickly identified when they are present, Cohen said.
Implementing these recommendations now will make it harder for manufacturers of sex supplements to sell their potentially dangerous products, he said.
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Rachael is a Live Science contributor, and was a former channel editor and senior writer for Live Science between 2010 and 2022. She has a master's degree in journalism from New York University's Science, Health and Environmental Reporting Program. She also holds a B.S. in molecular biology and an M.S. in biology from the University of California, San Diego. Her work has appeared in Scienceline, The Washington Post and Scientific American.