Dietary Supplements: Side Effects and Drug Interactions

Dietary supplements may seem safe or mild because they’re natural. Many think that something natural couldn’t hurt them.

Yet, serious side effects and drug interactions can occur when taking dietary supplements.

For example, supplements such as aloe vera, fenugreek, and vanadium may cause excessive bleeding during surgery or interact with anesthetics.

Other supplements may interfere with prescription medications. For example, ginseng may interfere with the drug warfarin’s ability to prevent blood clotting.

St. John’s wort, which people often take for depression, can interact with antidepressants, as well as many other prescription medications.

Your health care provider is the best resource for assessing the risks and benefits of taking a dietary supplement. He or she should know the potential side effects of supplements—and the risk for interactions with your other medications.

Next: Talking to Your Health Care Provider


This material is adapted from The American Diabetes Association Guide to Herbs & Nutritional Supplements, written by Laura Shane-McWhorter, PharmD, BCPS, FASCP, BC-ADM, CDE, and published by the American Diabetes Association, ©2009.

  • Last Reviewed: February 20, 2014
  • Last Edited: May 14, 2014

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