The use of herbal supplements has a long history - dating back thousands of years. Examples of important medicines extracted from botanicals include reserpine, morphine, penicillin, and vinca alkaloid anti-cancer drugs. Today, herbal supplements can be purchased over-the-counter, but that does not always mean they are safe. While these products are intended to boost health, and may make claims to that effect, robust clinical studies may be lacking. Herbal supplements are sold in many different forms - dried leaves for teas, powdered, as capsules or tablets, or in solution.
Even though herbal supplements may be from plant or herb sources, the active ingredients can still be potent chemicals. Because of this, herbal supplements can have drug interactions, even with each other or with food or alcohol. Unfortunately, these products are not labeled with safety warnings, and it is difficult for a consumer to know if an interaction may occur. Herbal interactions with prescriptions can interfere with how the drug may be broken down in the body, enhance side effects of prescription medications, or block the intended therapeutic effect of a drug. Almost 20 percent of Americans currently take some type of herbal or non-herbal supplement.