L-arginine
L-arginine hydrochloride is a semiessential amino acid, semi because, in most cases, the human body produces as much l-arginine as it needs. It is synthesized naturally by some plants, most animals, and almost all humans. It has also been manufactured in laboratories, typically for oral supplementation. Premature infants may not be able to produce l-arginine therefore it needs to be supplemented. There are certain cases where supplementation of l-arginine is deemed necessary, typically in post-surgery and serious physical trauma situations such as burns.
L-arginine is found in most dairy products, pork, beef, poultry, seafood, wheat, granola, oatmeal, nuts, and other foods. L-arinine plays an essential part in several bodily functions including the healing of wounds and damaged tissue, removing ammonia from the body, white blood cell function, proper hormone function, and cell division.
L-arginine is supplemented to reduce blood pressure, to speed up the recovery time from wound and damaged tissue (especially broken bones), persistent leg pain caused by blocked arteries, mental decline (such as senile dementia), erectile dysfunction, and male infertility.
L-arginine is also included in formulations which deal with various issues including sensitive teeth, treatment of herpes outbreaks (though some studies suggest that l-arginine may also be helping the herpes virus proliferate quicker), migraine headaches, breast cancer, weight loss in AIDS cases, and infection prevention.
L-arginine is used experimentally to prevent the common cold, improving kidney function after a kidney transplant, improving athletic performance, boosting the immune system, and preventing inflammation of the digestive tract in premature infants.
The potential side-effects of L-arginine supplementation are quite serious, including low blood pressure, blood abnormalities, and potentially death (though this is usually from those supplementing l-arginine post heart attack, and then this is based on one, somewhat inconclusive, study.) Inhaled l-arginine is considered, by some sources, to increase lung inflammation and worsen asthma. Overdose and long term supplementation of l-arginine carries additional concerns, including death in children and potentially in allergy and asthma sufferers. There are other less serious side-effects associated with l-arginine supplementation, including diarrhea, bloating, abdominal pain, and gout.