5 Risky Herbal Supplements: St. John's Wort, Kava, Comfrey, Chaparral, and Pennyroyal

WebMD talks to experts about the potential risks of herbal supplements: St. John's wort, kava, comfrey, chaparral, and pennyroyal. Source - http://www.webmd.com/vitamins-and-supplements/features/risky-herbal-supplemen...