Do the claims on that bottle of weight-loss pills seem too good to be true? They probably are. It's easy to fall for the hype when a pill has been endorsed or even created by, say, a trusted TV doc. But experts warn that most diet pills simply don't work  -- and some may even be harmful. Researchers at the University of California at San Francisco recently found that an over-the-counter diet supplement that contained bitter orange (Citrus aurantium) increased the heart rate of users.

Another product in the study contained bitter orange and caffeine, and raised blood pressure as well as heart rate. These effects are similar to those seen with the controversial herb ephedra, which was temporarily banned from weight-loss aids but has recently crept back on the market. The bottom line, says study author Christine Haller, M.D.: "Diet supplements are not adequately tested for safety, and their benefits are unproven." Guess it's true that if it came in a bottle, everyone would have it.