Dodgy herbal supplements are a common cause of liver injury, with bodybuilding and weight-loss products among the worst offenders.
US drug-induced liver injuries linked to supplements jumped from 7% in 2003 to about 20% in 2014, a study has found.
And studies in Europe show similar increases.
Last year, two cases of severe liver toxicity in Australian men — involving green tea extract, garcinia cambogia and valerian — prompted calls for tighter regulation.
In a new analysis of 272 herbal dietary supplements, 51% had inaccurate labelling, according to researchers presenting their findings at the annual meeting of the American Association for the Study of Liver Diseases.
“Herbal supplements are a common cause of liver injury,” says lead author Dr Victor Navarro, a hepatologist based in Philadelphia.
Dr Navarro is part of a group of investigators known as the Drug-Induced Liver Injury Network, supported by the US National Institute of Diabetes and Digestive and Kidney Diseases, which collects cases of drug-induced liver injury.
He says that, in 20% of cases, the injury is caused by dietary supplements.
Many of the products are sold as bodybuilding supplements or weight-loss supplements, he adds.
All of these cases have been reported to the US regulator, the Food and Drug Administration, but Dr Navarro says the next step is to build a stronger causality argument.
“We’ve identified some products we’re convinced cause liver injury, but right now it’s very circumstantial,” he says.
In Australia, herbal and dietary supplements are regulated by the TGA.