Ornithine is a non-essential amino acid derived from the breakdown of arginine during the citric acid cycle. It helps build muscle and reduce body fat, especially when combined with the amino acids arginine
is also needed for the formation of citrulline, proline
, and glutamic acid
, three amino acids that help supply energy to every cell in the body.
Ornithine is often combined with arginine and marketed to body builders as a muscle-building supplement. Laboratory studies have shown that ornithine increases both insulin and growth hormone levels, which are needed to build and maintain muscle during intensive physical training. Ornithine may also help combat the muscle loss that is a normal part of the aging process. As the body ages, it is less efficient at synthesizing proteins and can’t regenerate muscle tissue as quickly—strength and muscularity begin to decline. By helping to elevate growth hormone levels, ornithine may help speed the production of muscle tissue and offset the effects of aging. Although both arginine and ornithine help protect and build muscle mass, ornithine is generally thought to be twice as effective at stimulating growth hormone production as arginine, so a combination supplement is not necessary if you wish to use ornithine for this purpose.
Ornithine helps remove toxic ammonia from the liver, and may reduce the effects of cirrhosis of the liver and disorders associated with liver malfunction. In one study, participants taking 18 grams of ornithine aspartate for two weeks showed significant improvement in blood tests and liver function compared to the placebo group. Research has also shown that ornithine helps promote healing and tissue repair. Clinical studies reported that taking 10 grams of ornithine alpha-ketoglutarate (OKG) each day helped reduce the length of hospital stays for those recovering from surgery, generalized infections, cancer, trauma, and burns.
Ornithine is a nonessential amino acid, which means the body is able to produce its own supply. You can also get ornithine from your diet; meat, fish, dairy products, and eggs are also good sources of this nutrient. Few people are really deficient in ornithine, unless they are extremely malnourished or have a disorder that disrupts the citric acid cycle; however, if you wish to try ornithine supplementation for the purpose of increasing your body’s muscle content, or to fight the effects of aging, you can purchase supplemental ornithine capsules or powders at your local health food store and, in many cases, your local pharmacy. Ornithine is also included in many sport and protein drinks marketed for fat burning and muscle building. No side effects have been reported with the use of ornithine, although gastrointestinal distress may develop with intakes over 10 grams per day.