Chlorhydrate d'Ornithine, L-Ornithine, L-Ornithine HCl, L-Ornithine Hydrochloride, L-5-aminorvaline, L-2,5-diaminovaleric acid, Ornithine HCl, Ornitina.


Overview Information

Ornithine is a chemical called an amino acid. It is made in the body. It can also be made in a laboratory. People use it as a medicine.

Ornithine is commonly used by mouth for improving athletic performance. It is also used for weight loss, wound healing, and to increase sleep quality. But there is limited scientific research to support these other uses.

Don't confuse ornithine with ornithine alpha-ketoglutarate (OKG) or L-Ornithine-L-Aspartate.

How does it work?

It's not known how ornithine might work for medical uses. However, ornithine might help to increase levels of the amino acid, arginine. It might also increase levels of hormones that increase muscle size.


Uses & Effectiveness?

Possibly Effective for

  • Athletic performance. Taking ornithine by mouth might reduce fatigue and improve measures of athletic performance such as speed, strength, and power in some people. Taking ornithine in combination with arginine also seems to improve strength and power in male weightlifters.

Insufficient Evidence for

  • Dry skin.
  • Insomnia.
  • Obesity.
  • Wound healing.
  • Other conditions.
More evidence is needed to rate the effectiveness of ornithine for these uses.

Side Effects

Side Effects & Safety

When taken by mouth: Ornithine is POSSIBLY SAFE when taken by mouth at doses of up to 500 mg daily for up to 8 weeks.

Special Precautions & Warnings:

Pregnancy and breast-feeding: There isn't enough reliable information to know if ornithine is safe to use when pregnant or breast-feeding. Stay on the safe side and avoid use.



We currently have no information for ORNITHINE Interactions.



The following doses have been studied in scientific research:



  • For athletic performance: 1 gram twice/day for 7 days, then 3 grams with breakfast and lunch prior to exercise or athletic event. A single dose of ornithine hydrochloride 0.1 gram/kg taken prior to exercise or athletic event has also been used. Some people may take 1 gram of ornithine with 1 gram of arginine per day.

View References


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  • Horiuchi M, Kanesada H, Miyata T, et al. Ornithine ingestion improved sleep disturbances but was not associated with correction of blood tryptophan ratio in Japanese Antarctica expedition members during summer. Nutr Res 2013;33(7):557-64. View abstract.
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  • Manufacturer: Twinlab. Ronkonkoma, NY.
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