Do supplements really work or can they be dangerous?

According to a Consumer Reports survey, 60 percent of adults in the U.S. take at least one dietary supplement every day. But do these supplements really work, and can they be dangerous?

“It is difficult to know if a supplement is actually working, especially if you are making medication or lifestyle changes at the same time,” said Consumer Reports Investigative Reporter Lisa Gill.

Overall health

Besides vitamins and multivitamins, the most popular supplements Americans take to support overall health are fish oil, calcium, and probiotics.

“Research shows that taking fish oil can help reduce inflammation, that calcium supplements can help with bone health, and that probiotics can treat diarrhea from taking antibiotics. But so far, no research demonstrates that probiotics actually improve overall health,” Gill explained.

CONSUMER REPORTS: Do Popular Supplements Work?


When it comes to supplements taken to strengthen immunity, one of the most popular is zinc. But unless you are actually zinc deficient, you’re probably getting the recommended amount by eating a balanced diet.

“There is also evidence that a diet rich in antioxidants such as berries or blackberries, pumpkin, carrots, and cruciferous vegetables may support brain health,” said Gill.


Melatonin was by far the most popular supplement for sleep, and Consumer Reports says there’s a good reason.

“Taking melatonin can help you fall asleep about 7 minutes faster, and studies show it’s particularly helpful for those with jet lag or sleep disorders. But to avoid interfering with the body’s own natural production of it, avoid taking high doses over long periods of time,” Gill said.

Hair, skin, and nails

After biotin, collagen was the second-most common supplement taken in the survey to make hair, skin, and nails healthier.

Risky supplements

Gill warns that some supplements come with serious side effects, like liver damage. Consumer Reports recommends avoiding chaparral, coltsfoot, and comfrey.

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In general, risk increases the larger the dosage and the longer the supplement is taken. Here is the full list of 10 risky supplements that Consumer Reports, with the help of a panel of doctors and researchers, says you should always avoid:

  1. Chaparral
  2. Coltsfoot
  3. Comfrey
  4. Germander
  5. Greater Celandine
  6. Kava
  7. Lobelia
  8. Pennyroyal Oil
  9. Usnic Acid
  10. Yohimbe