L-ornithine supplementation attenuates physical fatigue in healthy volunteers. And L-ornithine levels are low in blood of individuals with chronic fatigue syndrome. Another study of individuals with chronic fatigue syndrome showed high levels of L-ornithine in plasma. The two studies may differ due to one study testing blood while the other study tested plasma. Dysregulation of cell membrane L-ornithine transporters could explain both results.
Would supplementation with L-ornithine be of assistance to individuals with chronic fatigue syndrome? Maybe and maybe not. L-ornithine would always be taken with vitamin B6 and and creatine. L-proline is synthesized from L-ornithine via ornithine aminotransferase which is a vitamin B6 dependent enzyme. L-orrithine can inhibit creatine synthesis.
Chronic fatigue syndrome could be an epigenetic illness and treatments for epigenetic illnesses are ugly in terms of simplicity. In all likelihood L-ornithine, vitamin B6 and creatine taken alone will not work for chronic fatigue syndrome. .
Manganese levels would be tested in chronic fatigue syndrome. Arginase which synthesizes L-ornithine is a manganese containing enzyme. Manganese levels have not been studied is chronic fatigue syndrome. If manganese levels are low in chronic fatigue syndrome almost certainly additional supplements would be required.
There are these two articles to consider Retinal risks of high-dose ornithine supplements: a review and Effect of long-term treatment of L-ornithine on visual function and retinal histology in the rats. Gyrate atrophy, which is a disease of the retina, results from a mutation in ornithine aminotransferase which results in high L-ornithine levels.
L-ornithine, L-lysine and L-arginine share the same transporter. High dosages of L-ornithine could competitively inhibit transport of L-lysine and/or L-arginine. Moderate dosages of L-ornithine would be taken if taken.