A peer-reviewed study published in Clinical Toxicology this week warns competitive athletes—and cardiac patients—against consuming supplements that might contain higenamine, a stimulant that’s poorly regulated and could pose a considerable threat to heart health.
The research, led by scientists at NSF International, Harvard Medical School and the National Institute for Public Health and the Environment in the Netherlands, studied 24 products labeled as containing higenamine, a beta-2 agonist that was banned two years ago by the World Anti-Doping Agency. And the substance doesn’t just increase risk for adverse events in athletes—it’s also commonly found in weight-loss and energy supplements.
“Beyond the doping risk for athletes, some of these products contain extremely high doses of a stimulant with unknown safety and potential cardiovascular risks when consumed,” John Travis, a senior research scientist at NSF International and co-author of the study, said in a release. “What we’ve learned from the study is that there is often no way for a consumer to know how much higenamine is actually in the product they are taking."
Indeed, in their review, Travis and his colleagues found just five products in 24 that listed a specific quantity of higenamine, and none of those quantities were accurate. Traces of the stimulant varied from none to 62 milligrams per serving based on the product, but the researchers said their calculations showed users could be exposed to up to 110 milligrams of the substance a day.
Co-author Pieter Cohen, MD, an associate professor of medicine at Harvard Medical School and an internist at Cambridge Health Alliance, said the health risks of higenamine aren’t well understood.
“Higenamine is a stimulant found in plants,” he said in the release. “When it comes to higenamine, we don’t yet know for certain what effect high dosages will have in the human body, but a series of preliminary studies suggest that it might have profound effects on the heart and other organs.”
Travis said higenamine is considered legal as a dietary ingredient when present as a constituent of botanicals, but his team found its dosage information to be widely misrepresented on product labels. And, as he pointed out, it’s a WADA-prohibited substance, so any amount could be considered harmful.
“We’re urging competitive and amateur athletes, as well as general consumers, to think twice before consuming a product that contains higenamine,” he said.