Ornithine

Related Terms

(+)-(S)-2,5-Diaminopentanoic acid, (+)-(S)-2,5-diaminovaleric acid, amino acid, guanidinium, L-arginine, L-norvaline, L-ornithine, L-ornithine-L-aspartate, ornithine (VAN), ornithine hydrochloride, ornithinum (Latin), putrescine, (S)-ornithine, urea.

Background

Ornithine is an amino acid found in the human body. It is made when the body disposes of excess nitrogen in the urine.
Ornithine has been shown to stimulate energy and growth hormone, which makes it of interest to bodybuilders. It has been used to improve performance during exercise. However, studies have shown mixed results when using ornithine hydrochloride to improve exercise performance.
Ornithine is combined with a compound called amino acid aspartate to improve liver health. Although research supports the use of ornithine for liver problems, more evidence is needed before further conclusions can be made.

Evidence Table

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. GRADE *
These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. GRADE *


The use of L-ornithine-L-aspartate has helped reduce harmful levels of ammonia in the body, which may help ease symptoms of liver problems. However, more evidence is needed to confirm this potential benefit.

 C


The use of L-ornithine-L-aspartate has helped reduce harmful levels of ammonia in the body, which may help ease symptoms of liver problems. However, more evidence is needed to confirm this potential benefit.

 C


L-ornithine-L-aspartate may help people who have ornithine deficiency caused by disease. More high-quality human studies are needed before conclusions can be made.

 C


L-ornithine-L-aspartate may help people who have ornithine deficiency caused by disease. More high-quality human studies are needed before conclusions can be made.

 C


Limited research suggests that ornithine in combination with other substances may improve physical performance in women, but the results are mixed. More clinical trials are needed to study the potential benefits of ornithine alone.

 C


Limited research suggests that ornithine in combination with other substances may improve physical performance in women, but the results are mixed. More clinical trials are needed to study the potential benefits of ornithine alone.

 C


L-ornithine-L-aspartate has been studied to treat brain problems that occur because the liver can no longer remove toxins from the blood. This combination may improve brain function and quality of life, but more studies are needed before conclusions can be made.

 C


L-ornithine-L-aspartate has been studied to treat brain problems that occur because the liver can no longer remove toxins from the blood. This combination may improve brain function and quality of life, but more studies are needed before conclusions can be made.

 C


L-ornithine-L-aspartate combined with other therapies has been studied in the treatment of liver diseases. Clinical trials are needed to determine the effects of ornithine alone.

 C


L-ornithine-L-aspartate combined with other therapies has been studied in the treatment of liver diseases. Clinical trials are needed to determine the effects of ornithine alone.

 C


Taking ornithine in addition to creatine supplements and avoiding arginine intake may benefit people with movement disorders. However, further research is needed.

 C


Taking ornithine in addition to creatine supplements and avoiding arginine intake may benefit people with movement disorders. However, further research is needed.

 C
* Key to grades

A: Strong scientific evidence for this use
B: Good scientific evidence for this use
C: Unclear scientific evidence for this use
D: Fair scientific evidence for this use (it may not work)
F: Strong scientific evidence against this use (it likley does not work)
* Key to grades

A: Strong scientific evidence for this use
B: Good scientific evidence for this use
C: Unclear scientific evidence for this use
D: Fair scientific evidence for this use (it may not work)
F: Strong scientific evidence against this use (it likley does not work)

Tradition / Theory

The below uses are based on tradition, scientific theories, or limited research. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. There may be other proposed uses that are not listed below.

Dosing

Adults (18 years and older)
To improve exercise performance, 1,000 milligrams of ornithine has been taken by mouth daily for seven days, followed by 3,000 milligrams after breakfast and lunch on the exercise test day. A dose of 0.1 grams of L-ornithine hydrochloride per kilogram of body mass has been taken by mouth after 30 seconds of exercise and before engaging in anaerobic cycle ergometer exercise, as well as by mouth as a one-time dose before physical activity.
To treat ornithine deficiency, one gram of ornithine has been taken by mouth daily as a food supplement.
To reduce blood ammonia levels, doses above five grams of ornithine have been taken by mouth.

Safety

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

Interactions

Interactions with Drugs
Ornithine may affect blood sugar levels. Caution is advised when using medications that may also affect blood sugar. People taking insulin or drugs for diabetes by mouth should be monitored closely by a qualified healthcare professional, including a pharmacist. Medication adjustments may be necessary.
Ornithine may also interact with agents that may affect the immune system, agents used for the liver, agents that may enhance exercise performance, agents that may regulate heart rate, anabolics (agents that may increase muscle strength), blood vessel widening agents, cholesterol-lowering agents, corticosteroids, dexamethasone, dexfenfluramine, growth hormones, hormonal agents, isoniazid, methohexital, weight loss agents, and wound-healing agents.

Attribution

This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

Bibliography

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