Millions of Americans spend billions of dollars annually on dietary supplements—herbal remedies, vitamins, minerals—to treat a multitude of ailments. But most don't know that under current law, there's no guarantee that what's on the label is what's in the bottle, or that what's in the bottle is safe and effective. In these excerpts from their interviews with FRONTLINE, experts discuss the controversy over regulating dietary supplements.

Even after ten years of federally funded research, very little is known about whether most alternative therapies work at all and which methods are safe. In these excerpts from their FRONTLINE interviews, researchers, practioners and skeptics discuss the scant evidence we have and why it's so hard to come by.

Critics of alternative medicine often dismiss reports of successful treatments by attributing the success to the "placebo effect": if the patient feels better, it's because he believes the therapy will work, not because of any actual physiological effect. Does it really matter? Medical historian James Whorton, alternative practioner Andrew Weil, and Harvard University's Marcia Angell and Tom Delbanco discuss the controversy.

The myriad of alternative and complementary therapies all share an approach to healing that aims to harness the innate healing power of the body and emphasizes practical results rather than rational, theoretical explanations. In these excerpts from their interviews, medical historian James Whorton, alternative practitioner Andrew Weil and conventional doctor—and skeptic—Marcia Angell discuss and critique this "alternative" worldview.

In 1993, a landmark study by Dr. David Eisenberg revealed that an astonishing one in three Americans had used some form of alternative or complemetary medicine, most of them without informing their physicians. In these excerpts FRONTLINE explores the impetus behind this recent surge in interest in alternative therapies with Eisenberg, Harvard University's Marcia Angell and Tom Delbanco, alternative practioner Andrew Weil and medical historian James Whorton.

Many hospitals today offer a variety of nonconventional treatments, and dozens of medical schools offer courses in alternative systems. Proponents of this integrative approach argue that it is simply an attempt to provide patients with the most comprehensive care available. Critics believe it's unethical for medical professionals to offer scientifically unproven treatments, and allege that for hospitals and medical schools, it's all about the bottom line. In these interview excerpts, experts on both sides debate the pros and cons of "integrative medicine."