Just because they're natural doesn't mean they're safe. Herbal supplements can have harmful effects when taken in improper doses or when mixed with other herbs or medications. Until recently, it's been a bit of a guessing game, but there is now a guide to navigating the confusing landscape of herbal dos and don'ts.
The Essential Guide to Herbal Safety is 704 pages of comprehensive information on the safety of 125 herbs, covering everything from interactions and adverse reactions to toxicity and allergies.