Nonessential Micronutrient



Ornithine, often partnered with arginine, stimulates growth-hormone release, possibly increasing muscle mass, strength, and energy, while decreasing bodyfat.

Other names for Ornithine


Where to find Ornithine

Meat, eggs, dairy products, and most other protein-rich foods contain the amino acid ornithine.


Why athletes use Ornithine

Ornithine is used by some power athletes in the hopes of enhancing growth-hormone levels, thereby increasing strength, muscle mass, and energy. While ornithine does appear to at least temporarily increase levels of growth hormone, claims of greater mass and strength are questionable. A more probable benefit may be improved recovery by flushing ammonia, a toxic byproduct of exercise, out of the body.

Ways that Ornithine can enhance Muscle Gain & Recovery:
  • Stimulate growth-hormone release to potentially increase muscle size and strength
  • Remove ammonia from the body to promote muscle recovery
Ways that Ornithine can enhance Longevity:
  • Support immune-system functioning and the body’s ability to remove toxins


Signs of Ornithine deficiency

No deficiency conditions are known to exist.
Potential uses for Ornithine

Research indicates that Ornithine may be useful in the treatment of:

* Wounds/injuries
* Trauma
* Liver disorders

More about Ornithine

You don’t usually hear about the amino acid ornithine without hearing about its partner arginine. This is because these two amino acids appear to work closely together to stimulate growth-hormone release, which has growth-enhancing and fat-mobilizing properties. And, ornithine is made in the body when arginine is used to produce urea (a part of urine). As such, it’s also important for removing ammonia from the body and promoting recovery.
What the research reveals

While the research is fairly controversial regarding this team’s beneficial effects, some research does suggest they may increase muscle mass, strength, and energy while decreasing bodyfat when combined with intense strength-training exercise. On the other hand, some scientists agree that ornithine appears to create a short burst of increased growth-hormone levels in the body but don’t believe this burst necessarily equals increased strength and muscle mass.

Researchers do appear to agree that ornithine is more likely to be depleted during periods of growth and injury or trauma and may support increased recovery when the body is adapting to stress. In fact, research studies have documented ornithine’s potential ability to improve healing. In addition, ornithine is believed to help support the immune system and even support liver regeneration by helping detoxify harmful substances.
Ornithine teams up with alpha-ketoglutarate

Ornithine appears to be more effective when combined in the form of ornithine alpha-ketoglutarate (OKG). This form may have stronger ammonia-scavenging benefits and generate greater growth-hormone release in healthy subjects.
In truth

Some experts contend that ornithine may be twice as effective as arginine at its job of promoting the release of growth hormone. So ornithine use with or without arginine may be a viable solution for stimulating growth-hormone release, at least temporarily. And researchers will likely continue examining what this release may mean in real-world situations.

500 mg of ornithine, combined with 1,000 mg of arginine, taken twice a day for at least 5 days is reportedly effective for some athletes to raise growth-hormone levels.

Ornithine and arginine are recommended in two divided dosages — once before exercise and once before sleep — on an empty stomach (or at least three hours away from any other amino acids).
Synergists of Ornithine

Growth-hormone release may be increased when ornithine is combined with arginine, choline, and pantothenic acid.

Some experts suggest ornithine is more efficient when combined with alpha-ketoglutarate.

When supplementing with ornithine, some experts recommend increasing antioxidant intake.
Safety of Ornithine

Over 10 grams a day may lead to an upset stomach.

Diabetics should use caution when using any products which may influence growth-hormone levels.

Ornithine should not be used by individuals with herpes infections as it may stimulate the virus.

People with certain psychoses should not supplement with ornithine as it may stimulate symptoms.

Some experts caution that ornithine may cause insomnia for some individuals.
Toxicity of Ornithine

No known toxicity.
Bans and restrictions

None reported.

* Bucci, L., et al., “Ornithine Ingestion and Growth Hormone Release in Bodybuilders,” Nutr Res 10 (1990) : 239-45.
* Bucci, L.R., et al., “Ornithine Supplementation and Insulin Release in Bodybuilders,” Int J Sport Nutr 2.3 (1992) : 287-91.
* Cynobar, L., et al., “Action of Ornithine Alpha-Ketoglutarate on Protein Metabolism in Burn Patients,” Nutrition 3 (1987) : 187-91.
* Elam, R.P., et al., “Effects of Arginine and Ornithine on Strength, Lean Body Mass, and Urinary Hydroxyproline in Adult Males,” J Sports Med Phys Fitness 29.1 (1989) : 52-6.
* Krassowski, J., et al., “The Effect of Ornithine-Alpha-Ketoglutarate on Insulin and Glucagon Secretion in Normal Subjects,” Acta Endocrinol 98.2 (1981) : 252-5.