By Jamie Ducharme
June 6, 2019

Supplements promising flashy results like weight loss, muscle building and energy are sending kids and young adults to the hospital, according to a study published in the Journal of Adolescent Health.

An analysis of Food and Drug Administration (FDA) records revealed that, from January 2004 to April 2015, about 1,000 people ages 25 and younger had a health issue linked to dietary supplements. About 40% of them were categorized as severe problems, resulting in 166 hospitalizations and 22 deaths. And those numbers may only be the “tip of the iceberg,” the authors write, since many issues go unreported.

Certain supplements appeared to be more dangerous than others. Supplements claiming to aid weight loss, muscle building and energy were almost three times more likely, and and those marketed for sexual function or colon cleansing were about twice as likely to contribute to a health problem than vitamins, the researchers found,

The authors note that some of these products have been shown to be tainted with undisclosed substances, including prescription drugs, heavy metals and pesticides. In 2015, for example, researchers found that some weight-loss supplements contained an amphetamine-like stimulant that was not on the label.

While the FDA can and does intervene when issues are reported with a particular product, the agency does not test the contents or safety of supplements before they hit the market. Instead, individual companies are responsible for meeting safety and manufacturing guidelines put forth by the FDA before they market their products.

As a result, customers must simply trust that the ingredients and claims listed on a product’s label are accurate, often without much outside validation. The FDA has repeatedly warned consumers about the risks of taking supplements that promise “miracle” results like dramatic weight loss and disease prevention or treatment. In severe cases, as the new study and papers before it show, supplements may be associated with heart issues, allergic reactions and harmful interactions with prescription medications, among other problems.

While multivitamins may be less likely to cause life-threatening health issues than other types of supplements, evidence increasingly suggests they’re not necessary for most people. One recent study found that they do not improve health and longevity as well as nutrients consumed through food, and that taking high doses of certain supplements, including calcium and vitamin D, may raise consumers’ risks of cancer and premature death. Other research has questioned claims made by vitamin D, fish oil and omega-3 supplement makers about their ability to ward off chronic conditions like cancer, cardiovascular disease and cognitive decline.

Write to Jamie Ducharme at jamie.ducharme@time.com.

Read More From TIME

EDIT POST