Here's How to Tell Whether Your Supplements Are Dangerous

Supplements live in the wild west of the wellness world. They’re largely unregulated and under-researched, so people are often left to make not-so-educated guesses about what they’re putting in their bodies.

Two new resources from the National Institutes of Health’s Office of Dietary Supplements (ODS) may help. On Wednesday, it released two new fact sheets — one for exercise and athletic performance supplements, and another for weight loss supplements — meant to help people determine what’s safe and effective.

Each fact sheet lists common dietary supplements used for a specified purpose — like creatine, protein supplements and tart cherry juice for fitness, and caffeine, green tea extract and capsaicin for weight loss — as well as a summary of the science, however minimal, available on that substance. The tools are meant to guide people as they try to improve their health, and steer them away from ineffective or unsafe ingredients.

On the whole, more fitness supplements got the green light than weight loss supplements. Evidence supports the use of creatine, beet juice and caffeine for at least some types of athletes, while things like deer antler velvet were called out for inadequate evidence. Most of the weight loss supplements were associated with very modest results at best, while others — including bitter orange and green tea extract — carried safety warnings.

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“Dietary supplements marketed for exercise and athletic performance can’t take the place of a healthy diet, but some might have value for certain types of activity,” said ODS director Paul Coates in a statement. “Others don’t seem to work, and some might even be harmful.”

Supplement sales are projected to approach $300 billion by 2024, but many experts remain skeptical of how effective they really are, since there’s not a lot of information about what they actually contain and how, or if, they work. One study even estimated that supplement misuse leads to 23,000 emergency room visits each year.

You can learn more about the new fact sheets here.

Correction: The original version of this story misidentified a National Institutes of Health office. It is the Office of Dietary Supplements, not the Office of Dietary Substances. The story also misstated the expected growth in supplement sales. Supplement sales are projected to approach $300 billion by 2024, not $300 million.

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