INDIANAPOLIS (WISH) — About 59 million Americans use some type of vitamins or supplements regularly.

But a new study shows some supplements may be putting your health at risk.

Pills, powders, gummies, shakes; Americans are all in when it comes to supplements. But many of the popular ones haven’t been proven to work.

“So many individuals are taking these when many well-done clinical trials have shown that these supplements are no better than placebo,” said Dr. Erin Michos, associate professor of medicine at Johns Hopkins University School of Medicine.

A new study published in JAMA Network Open found that at least 15.6 million U.S. adults may have consumed an herbal product that could damage their liver in the last 30 days. The six worst offenders were: turmeric, green tea, ashwagandha, garcinia cambogia, red yeast rice, and black cohosh.

“The data for both calcium supplements and many other types of supplements and multivitamins, you know, it’s not clear at all for any kind of cancer benefit or cardiovascular benefit,” Michos said.

A big problem with supplements is the FDA doesn’t evaluate them for safety, effectiveness, or quality. The new study found some of the herbal products had discrepancies between their ingredient lists and what was actually in them. The best way to ensure quality is to look for products that have been certified by a third-party company, such as NSF, USP, BSCG, or consumer-lab.

And before using a supplement:

“I think individuals should talk to their doctors about do they need these supplements and why are they taking them,” Michos said.

The authors of the study noted that liver damage connected to herbal and dietary supplement use has been increasing, now accounting for more than 20% of liver injuries. Severe liver problems can lead to the need for a transplant or even death.

This story was created from a script aired on WISH-TV. Health Spotlight is presented by Community Health Network.