L-Ornithine
Also known as: ornithine, L-ornithine HCl, ornithine hydrochloride
A non-protein amino acid central to the urea cycle, where it helps clear ammonia produced during exercise and protein metabolism. Small Japanese trials have studied it for reduced physical fatigue after prolonged exercise and for stress and sleep quality in workers. It appears in recovery, sleep, and liver-support formulas and is usually supplied as the hydrochloride salt.
Research summary
Urea-cycle intermediate that supports ammonia detoxification; may modulate cortisol and fatigue-related amino-acid metabolism.
Dosage
Daily amounts, of compound.
| Lowest studied | Typical range | Highest studied | Upper limit |
|---|---|---|---|
| 400 mg | 400–2,000 mg | 2,000 mg | — |
The fatigue trial used 2,000 mg/day of L-ornithine hydrochloride for about a week; a stress and sleep trial used 400 mg/day. Doses here are of ornithine HCl, which is roughly 78% ornithine by mass. Take in the evening for sleep-oriented formulas.
Source material: fermentation-derived (as L-ornithine HCl)
As supplied: L-ornithine HCl supplies about 78% ornithine by mass.
Format suitability
- Capsule
- Powder
- Tablet
- Softgel
- Gummy
- Liquid
Soluble and mildly bitter; 1 g fits in about two size-00 capsules.
Formulation notes
Frequently paired with arginine (as in older growth-hormone-support stacks) and with citrulline in ammonia-clearance formulas.
Sources
Related ingredients
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Typical: 200–350 mg
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Typical: 100–300 mg
Ashwagandha Root Extract (KSM-66)
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