L-ornithine is sometimes used as a nutritional supplement for its putative anabolic activity, even though there is little evidence to support this. However, there is a derivative of L-ornithine called ornithine alpha-ketoglutarate or OKG which, under certain conditions, may have immunomodulatory and anticatabolic and/or anabolic actions.

L-Ornithine may be very helpful if you are trying to lose fat. It is important because it initiates the release of growth hormone in the body. This can be very helpful with fat metabolism.