Research
L-Ornithine
9 peer-reviewed studies curated from PubMed and Semantic Scholar.
Studies
Sorted by quality and recency
Safety assessment of L-ornithine oral intake in healthy subjects: a systematic review.
Systematic review assessing the safety of L-Ornithine oral intake in healthy subjects. The review included 22 articles, with a maximum dose of 14,025 mg/person/day and a maximum duration of 156 days. The main observed adverse events were gastrointestinal disorders, but no significant effects were observed in the risk of these disorders with L-Orn supplementation.
L-ornithine supplementation in periodontitis treatment yields greater benefits than L-arginine after one year: Part II of a randomized controlled pilot study.
RCT assessing the long-term efficacy of L-ornithine and L-arginine as adjuncts to periodontal therapy in 75 patients with periodontitis. After one year, L-ornithine showed greater clinical benefits than L-arginine, with significant reductions in periodontal pocket depth and increased macrophage density.
The effects of acute and chronic oral tea catechins and ornithine supplementation on exercise-induced ammonia accumulation and cycling performance in healthy young men: a randomized, double-blind, cross-over, placebo-controlled trial.
RCT with 16 healthy young men examining the effects of acute and chronic oral intake of tea catechins and ornithine on exercise-induced ammonia accumulation and cycling performance. The study found no suppression of ammonia accumulation or enhancement of cycling performance, though subjective fatigue was lower with supplementation.
Randomised controlled trial of the effects of L-ornithine on stress markers and sleep quality in healthy workers.
RCT of 52 healthy Japanese adults assessing the effects of L-ornithine (400 mg/day) on stress and sleep quality over 8 weeks. L-ornithine supplementation significantly decreased serum cortisol levels and improved perceived sleep quality and mood.
A randomized, double-blind and placebo-controlled crossover trial on the effect of l-ornithine ingestion on the human circadian clock.
A randomized, double-blind, placebo-controlled crossover trial examined the effect of L-ornithine ingestion on the human central circadian clock in 28 healthy adults. The study found that dim light melatonin onset, a marker of central circadian phase, was delayed by 15 minutes after L-ornithine ingestion, indicating that L-ornithine affects the human central clock.
Effects of Composite Supplement Containing Collagen Peptide and Ornithine on Skin Conditions and Plasma IGF-1 Levels-A Randomized, Double-Blind, Placebo-Controlled Trial.
RCT of 22 healthy Japanese participants testing a composite supplement containing collagen peptide and ornithine (CPO) over 8 weeks. The CPO group showed significant improvements in skin elasticity and transepidermal water loss, as well as increased plasma IGF-1 levels compared to placebo.
Effect of L-ornithine hydrochloride ingestion on intermittent maximal anaerobic cycle ergometer performance and fatigue recovery after exercise.
RCT examining the effect of L-ornithine hydrochloride ingestion on ammonia metabolism and performance after intermittent maximal anaerobic cycle ergometer exercise in 10 healthy young adults. L-ornithine hydrochloride ingestion improved peak rpm and serum ornithine levels compared to placebo, suggesting enhanced anaerobic performance and recovery.
L-ornithine supplementation attenuates physical fatigue in healthy volunteers by modulating lipid and amino acid metabolism.
Double-blind, placebo-controlled, 2-way crossover study with 17 healthy volunteers examining L-ornithine supplementation on physical fatigue. L-ornithine administration promoted lipid metabolism and activated the urea cycle, significantly attenuating subjective fatigue and improving physical performance in female subjects compared to placebo.
Ornithine supplementation and insulin release in bodybuilders.
RCT with 12 bodybuilders testing the effect of oral ornithine supplementation on insulin release. Serum ornithine levels increased, but serum insulin did not change from baseline at any dose, indicating ornithine is not an insulin secretagogue.