Ornithine helps to promote the release of growth hormone, which promotes the metabolism of excess body fat. This effect is enhanced if ornithine is combined with arginine  and carnitine. Ornithine is necessary for proper immune system and liver function. This amino acid also  detoxifies ammonia and aids in liver regeneration. High concentrations of ornithine are found in the skin and connective tissue, making it useful for promoting healing and repairing damaged  tissues.  

Ornithine is synthesized in the body from arginine, and in turn serves as the precursor of  citrulline, proline, and glutamic acid.