Herbal Remedies Found to Contain Toxic Heavy Metals

Join Our Community of Science Lovers!


On supporting science journalism

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.


Some herbal remedies may do more harm than good. Researchers writing today in the Journal of the American Medical Association report that 20 percent of herbal medicine products sampled contained dangerous levels of heavy metals.

Unlike prescription drugs, herbal medicine products can be sold as dietary supplements, which are not required to undergo rigorous testing before entering the marketplace. Indeed, the Dietary Supplement Health and Education Act (DSHEA) does not require proof of safety or efficacy. Robert B. Saper, now at Boston University's School of Medicine, and his colleagues purchased imported Ayurvedic herbal medicine products from stores near Boston's city hall and had them tested for metal contamination. They discovered that a fifth of the 70 samples tested contained lead, mercury or arsenic, or some combination of all three, in significant quantities. If taken as directed, the products would expose a person to more of the metals than is deemed safe by the Environmental Protection Agency.

"Although the prevalence of heavy metal-containing Ayurvedic [herbal medicine products] is unknown, the number of individuals at potential risk is substantial," the team writes. "Our findings support calls for reform of DSHEA that would require mandatory testing of all imported dietary supplements for toxic heavy metals."

It’s Time to Stand Up for Science

If you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in that two-century history.

I’ve been a Scientific American subscriber since I was 12 years old, and it helped shape the way I look at the world. SciAm always educates and delights me, and inspires a sense of awe for our vast, beautiful universe. I hope it does that for you, too.

If you subscribe to Scientific American, you help ensure that our coverage is centered on meaningful research and discovery; that we have the resources to report on the decisions that threaten labs across the U.S.; and that we support both budding and working scientists at a time when the value of science itself too often goes unrecognized.

In return, you get essential news, captivating podcasts, brilliant infographics, can't-miss newsletters, must-watch videos, challenging games, and the science world's best writing and reporting. You can even gift someone a subscription.

There has never been a more important time for us to stand up and show why science matters. I hope you’ll support us in that mission.

Thank you,

David M. Ewalt, Editor in Chief, Scientific American

Subscribe