Also indexed as: L-Ornithine-L-Aspartate, OA,
Ornithine, an amino acid, is manufactured
by the body when another amino acid, arginine,
is metabolized during the production of urea (a constituent of urine).
Where is it found?
As with amino acids in general, ornithine
is predominantly found in meat, fish,
dairy, and eggs. Western diets typically
provide 5 grams per day. The body also produces ornithine.
Ornithine has been used in
connection with the following conditions (refer to the individual
health concern for complete information):
(hepatic encephalopathy) (L-ornithine-L-aspartate)
Recovery from illness (ornithine alpha-ketoglutarate)
(for body composition and strength)
Who is likely to be deficient?
Since ornithine is produced by the body, a deficiency of this nonessential amino acid is unlikely, though depletion can occur
during growth or pregnancy, and after severe
trauma or malnutrition.1
How much is usually taken?
Most people would not benefit from ornithine supplementation. In human research involving
ornithine, 5–10 grams are typically used per day, sometimes combined with arginine.
Are there any side effects or interactions?
No side effects have been reported with the use of ornithine, except for gastrointestinal
distress with intakes over 10 grams per day.
The presence of arginine is needed to
produce ornithine in the body, so higher levels of this amino acid should increase ornithine production.
At the time of writing, there were no well-known drug interactions
1. Zieve L. Conditional deficiencies of ornithine or arginine. J Am
Coll Nutr 1986;5:167–76. [review]