Arginine is a vitally important amino acidthat has been studied for more than fifty years. Amino acids are the building blocks of protein, and protein is the building block of all living cells. The greatest portion of human body weight, after water, is protein. On the cellular level, the principal function of DNAis to provide the "blueprints" for production of hundreds of different proteins, each constructed from unique sequences of amino acids that are held together by peptidebonds. There are more than twenty commonly known amino acids, and additional amino acids are periodically identified, classified, and studied.

A healthy liver can produce approximately 80 percent of the body's required amino acids. They are termed the "nonessential" amino acids, not because they lack importance, quite the contrary, but because the body can synthesize them from other amino acids obtained from dietary sources. The human body, for example, can readily synthesize arginine to ornithine, or ornithine to arginine. The remaining 20 percent of amino acids required by humans are termed "essential" amino acids because they cannot be manufactured by the body and must be obtained from dietary sources. The body's ability to synthesize the nonessential amino acids such as arginine, and to utilize all amino acids, can be adversely affected by an individual's advancing age, overall health, organ health, the presence of infection, physical trauma such as injury, effects of stress, compromised nutrient absorptioncapacity, and imbalances of other nutrients.

The study of amino acids is making a major contribution to the understanding of diseases. Amino acid therapies have been used successfully to prevent aging, prevent heart disease, enhance memory, eliminate depression, control stress, improve sleep, relieve arthritis, reduce herpes, arrest alcoholism, manage allergies, and promote hair growth.

Arginine has been linked to enhanced immunity, the release of the Human Growth Hormone(HGH), greater muscle mass, rapid healing from injury, increased sexual potency, and helping to reverse atherosclerosis.

Sometimes one amino acid can cancel the effect of another. For example, arginine is reported to have an antagonistic relationship with lysine. On the other hand, arginine has a complementary relationship with ornithine, citrulline, and aspartic acid.