Book excerpt: Your Personal "MIRACLE DRUGS" The two dozen amino acids present in the human body are now being shown to be among the most potent healing substances ever discovered. These constituents of protein are necessary to every life process, but research and clinical work in the last two decades have revealed a vast range of therapeutic functions for amino acids, including: arginine's ability to improve sexual dysfunction phenylalanine's pain-relieving powers tyrosine's addiction-fighting potential and energizing action methionine's role in the treatment of Parkinson's disease and as an antidepressant tryptophan's promising use with hyperactivity cysteine's emergence as one of the body's best free-radical destroyers This update and revision of the landmark book on amino acids covers the exciting discoveries of the last decade and shows you how to use them in your personal health-management program.