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L-Ornithine Research & Evidence

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Evidence Level

Preliminary

L-Ornithine's role in the urea cycle is well-established biochemistry, but supplementation evidence is still emerging. The most robust clinical use is as LOLA for hepatic encephalopathy. For exercise and sleep, studies are promising but small. The sleep study showing improved quality with just 400 mg is notable for its low effective dose. More large-scale RCTs are needed to confirm exercise performance benefits.

Evidence by Condition

ConditionStudied DoseEvidence
Exercise fatigue2-6 g before prolonged exercisePreliminary
Sleep quality400 mg before bedPreliminary
Hepatic encephalopathy (LOLA)9-18 g/day L-ornithine-L-aspartateStrong
Full L-Ornithine Guide

References

  1. (). Randomised controlled trial of the effects of L-ornithine on stress markers and sleep quality in healthy workers. Nutrition Journal. DOI
  2. (). L-ornithine supplementation attenuates physical fatigue in healthy volunteers by modulating lipid and amino acid metabolism. Nutrition Research. DOI
  3. (). L-Ornithine L-Aspartate (LOLA) for Hepatic Encephalopathy in Cirrhosis: Results of Randomized Controlled Trials and Meta-Analyses. Drugs. DOI