The relationship between conventional allopathic medical care and the world of complementary and alternative medicine (CAM) remains ambiguous. Numerous surveys document continued high levels of interest in, use of, and expenditures for CAM modalities among the US public. Clinical scientists have responded by increasingly subjecting CAM interventions to the same methodologic scrutiny that has fostered conventional medicine's remarkable progress, with the preeminent standard of the double-blind, placebo-controlled clinical trial.