Ornithine is an amino acid that is made in the body. It's not used to create protein, but plays a role in other processes. It can also be made in a lab.

Ornithine might help to increase levels of another amino acid called arginine. It might also increase levels of hormones that increase muscle size.

People use ornithine for athletic performance, dry skin, insomnia, wound healing, and other purposes, but there is no good scientific evidence to support most of these uses.

Don't confuse ornithine with ornithine alpha-ketoglutarate (OKG) or L-Ornithine-L-Aspartate. These are not the same.

Uses & Effectiveness ?

Possibly Effective for

  • Athletic performance. Taking ornithine by mouth might reduce fatigue and improve some measures of athletic performance.
There is interest in using ornithine for a number of other purposes, but there isn't enough reliable information to say whether it might be helpful.

Side Effects

When taken by mouth: Ornithine is possibly safe when used at doses up to 500 mg daily for up to 8 weeks.

Special Precautions and Warnings

When taken by mouth: Ornithine is possibly safe when used at doses up to 500 mg daily for up to 8 weeks.

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.

Interactions ?

We currently have no information for ORNITHINE overview.


There isn't enough reliable information to know what an appropriate dose of ornithine might be. Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult a healthcare professional before using.

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CONDITIONS OF USE AND IMPORTANT INFORMATION: This information is meant to supplement, not replace advice from your doctor or healthcare provider and is not meant to cover all possible uses, precautions, interactions or adverse effects. This information may not fit your specific health circumstances. Never delay or disregard seeking professional medical advice from your doctor or other qualified health care provider because of something you have read on WebMD. You should always speak with your doctor or health care professional before you start, stop, or change any prescribed part of your health care plan or treatment and to determine what course of therapy is right for you.

This copyrighted material is provided by Natural Medicines Comprehensive Database Consumer Version. Information from this source is evidence-based and objective, and without commercial influence. For professional medical information on natural medicines, see Natural Medicines Comprehensive Database Professional Version.
© Therapeutic Research Faculty 2020.