According to the U.S. Food and Drug Administration (FDA), an estimated 38 million Americans have used a fraudulent health product within the past year. From copper bracelets for arthritis to herbal tea as a cure for AIDS, unproved, even dangerous health products are more difficult to spot than most people realize. Even doctors can have trouble identifying an ineffective or unproven product if it does not fall within their specialty or area of expertise. And these products are not without risks. According to one survey, one out of 10 people who try such remedies are harmed by adverse side effects.

The best protection? Information. Evaluate health claims carefully, and be aware of phrases and promises that may signal trouble.