Why supplements may hurt your health more than help

When to beware of supplements

As the supplement industry has grown to meteoric heights, so have the downstream side effects: 20 percent of drug-induced liver injury in the United States is now related to herbal and dietary supplements, with some analyses putting the number as high as 43 percent. Meanwhile, the number of people on the U.S. transplant list with drug-induced liver failure related to supplements rose from one to 7 percent between 1995 and 2020. This is a massive uptick—a seven-fold increase—over 25 years.

Recent media reports spotlight patients ending up in the emergency room with yellow eyes, abdominal pain, fatigue—symptoms of liver failure linked to supplement intake, even from reportedly “clinically-validated” brands. 

Certain supplements have been linked to these effects, including green tea extract, often found in weight-loss supplements or metabolism “boosters;” bodybuilding supplements sometimes tainted with anabolic steroids; and multi-ingredient nutritional supplements used for a range of purposes from hair growth to mental health. 

These ingredients are common: In 2024, researchers found that 15 million Americans take compounds known to be toxic to the liver: turmeric, ashwagandha, black cohosh, garcinia cambogia, green tea, and red yeast rice.

(The benefits—and downsides—of taking ashwagandha.)

“While things like simple vitamins and minerals are generally okay, with some points of caution [niacin can be hepatotoxic in high doses], I would generally avoid anything with herbal or botanical ingredients,” Ghabril says.

These offending agents impact health in myriad ways: Green tea extract can inflame the liver, while bodybuilding supplements can slow or stall bile fluid. Multi-ingredient supplements are trickier to study health-wise, as it’s difficult for scientists to isolate their active components.     

Mislabeling and adulteration run rampant across the supplement industry, too, making it challenging to pinpoint side effects. Users often mix and match supplements with multiple bioactive ingredients, sometimes taking them at super-high doses or with other drugs, while manufacturers swap in cheaper ingredients to lower costs. 

In rare cases, analyses have revealed supplements contaminated with heavy metals like lead and arsenic, synthetic drugs, bacteria, yeast and fungi—agents which are linked to dementia, infection, brittle bones, and appendicitis, especially in the elderly or those with compromised immune function.