Nutrition Supplements: Science vs Hype.

Aggressive marketing has led millions of recreational and elite athletes to use nutrition supplements in hopes of improving performance. Unfortunately, these aids can be costly and potentially harmful, and the advertised ergogenic gains are often based on little or no scientific evidence. No benefits have been convincingly demonstrated for amino acids, L-carnitine, L-tryptophan, or chromium picolinate. Creatine, beta-hydroxy-beta-methylbutyrate, and dehydroepiandrosterone (DHEA) may confer ergogenic or anabolic effects. Chromium picolinate and DHEA have adverse side effects, and the safety of the other products remains in question.