Complementary and alternative medicine encompasses a wide range of modalities, including acupuncture, herbs and supplements, naturopathy, and body and mind therapies. The use of these healing methods is increasing rapidly, and more and more patients are approaching primary care physicians with questions about them. The purpose of this issue is to help doctors understand the evidence supporting and refuting complementary and alternative medicine techniques so they can provide patients with answers. This is the first of a two-part series, and it focuses on the various modalities.