Ornithine is a dispensable amino acid that does not occur in proteins. Its primary role in the body is in the urea cycle, which makes it important in the removal of ammonia. It is formed from arginine in the urea cycle.
It is proven to be an effective releaser of growth hormone. It is this role that has brought it widespread recognition among athletes in recent years.
Supplementation with L-ornithine in various dosages, ranging from 2,000 to 4,000 milligrams per day has been studied. A study using 1,000 milligrams of L-ornithine and 1,000 milligrams of L-arginine per day along with five weeks of weight training showed a decrease in body fat and an increase in muscle mass.
Another study examining the effects of bodybuilders taking just ornithine supplements reported an increase in growth hormone levels. Thus, ornithine supplements may be particularly beneficial for bodybuilders, powerlifters, sprinters and other strength athletes.
Ornithine is also proven to heal burn wounds among patients. This is because it helps increase the body's ability to heal tissue faster. Patients who suffer from brain abnormalities such as hepatic encephalopathy due to liver cirrhosis have also shown improvement when treated with ornithine.
In cases where supplementation of ornithine is necessary, five to ten grams daily would be typical.