Taking a Dietary Supplement?


Be sure to ask about potential interactions

If you’re taking medication and also take an herbal or other kind of dietary supplement, tell your doctor and/or pharmacist what you take and ask about possible interactions.

A dietary supplement, by definition, is a substance taken by mouth in whatever form (gel, capsule, tablet, powder, and so on), but is not a food. Dietary supplements can interact with both prescription and nonprescription medications, making the drugs less or more potent. For example, a wide range of supplements, including garlic, ginkgo, dong quai, and licorice root, can boost the effect of such drugs as warfarin (Coumadin), thus increasing the risk of bleeding. On the other hand, supplements such as vitamin K and ginseng reduce warfarin’s blood-thinning effect. Many other drugs may also have interactions with supplements.

In addition, if you take supplements, especially herbal ones, and are about to have surgery, talk to your doctor about whether you should stop taking them, since they can cause complications-just as prescription and over-the-counter drugs can.

Possible problems range from excessive bleeding to interaction with anesthetics. Your doctor may recommend stopping certain medications and supplements a week or even more before surgery. If surgery must be scheduled sooner, show all herbal products (in their packages) to your doctor beforehand.