Summary

OKG has been shown to support muscle building and inhibit muscle breakdown by boosting key growth hormones. It has also been shown to enhance wound healing and support immune function.

Other names for OKG

ornithine alpha-ketoglutarate, AKG, alpha-ketoglutarate

Where to find OKG

OKG is found only in supplements. However, the amino acids that make up OKG are found in meat, poultry, and fish.

Why athletes use OKG

OKG may aid the building of lean mass while preventing the breakdown of muscle and other tissues, which are often overtaxed by intense training. Athletes, among others, may also benefit from OKG's immune-supporting properties.

Ways that OKG can enhance Muscle Gain & Recovery:

• Boost levels of growth hormone and IGF to support muscle growth and recovery
• Fight off muscle wasting and support muscle recovery by increasing levels of glutamine
• Improve the body's recovery and wound-healing capability and speed

Signs of OKG deficiency

No deficiency conditions are known to exist.

Potential uses for OKG

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

• Catabolism (muscle wasting)
• Impaired immune function
• Wounds/injuries
• Retarded growth

More about OKG

Ornithine alpha-ketoglutarate (OKG) is an amino acid complex naturally produced in the body when the amino acids ornithine and glutamine combine. Studies suggest supplemental OKG may have muscle-building effects as well as potential to stave off muscle wasting.

How it works

Although the exact mechanisms of OKG are not fully understood, researchers believe it offers an anabolic (muscle-building) and anti-catabolic (anti-muscle-wasting) effect by boosting IGF-1 (insulin growth factor) and GH (growth hormone) levels.

Researchers also theorize that OKG contributes to the synthesis of key metabolites, including glutamine. The alpha-ketoglutarate portion of OKG is thought to contribute to glutamine synthesis, while the ornithine portion is thought to contribute to higher, more stable levels of glutamine. This positive effect on glutamine stores is significant because the depletion of glutamine, the most abundant amino acid in muscle tissue, has been shown to cause muscle wasting. Glutamine is also integrally involved in supporting healthy immune functioning.

Therapeutic uses

Supplemental OKG has been shown to slow protein loss and enhance muscle growth in hospitalized patients suffering from muscle wasting caused by burns as well as severe trauma. A number of studies show that OKG leads to a significantly better clinical recovery, including enhanced wound healing, probably through its anabolic and anti-catabolic effects.

In non-hospitalized elderly individuals, OKG has also been shown to improve appetite, reduce the need for medical care, boost muscle growth, increase weight, and improve the overall quality of life. In children suffering from slow growth (below the 50th percentile for their age), OKG was shown to boost insulin growth factor and glutamine concentrations, thereby accelerating growth.

In truth

Some researchers believe OKG may help stabilize muscle mass and limit injuries related to loss of strength and bodyweight in athletes as well. But keep in mind, the benefits of OKG have not yet been documented. The majority of the research has been conducted on hospitalized and non-hospitalized elderly populations, severe burn victims, and animals.

Nonetheless, there is evidence to suggest that OKG may offer benefits to athletes. Because injuries produce a catabolic state in which the body breaks itself down, OKG may help us safeguard against muscle loss due to overtraining or injury. OKG may also help us heal more quickly after injury and support muscle growth by boosting the production of key growth hormones.

Amount

Research studies have used 10 grams per day, but optimal levels have not yet been established. The Colgan Institute recommends 100 mg per kilogram of bodyweight for athletes.

Timing

Many studies administered large amounts in one daily dose (i.e., 10 grams) with a meal. Some experts recommend taking ornithine with a high-carbohydrate meal. Although the benefits of cycling have not been determined, cycling may be advantageous because the body may "down-regulate" OKG's benefits after continued use.

Synergists of OKG

No synergists have been noted.

Toxicity of OKG

Gastrointestinal upset may occur when taking 10 grams or more. Insomnia has also been reported at these higher amounts.

Bans and restrictions

None reported.

• Cynober, L., et al., "Action of Ornithine Alpha-Ketoglutarate, Ornithine Hydrochloride, and Calcium Alpha-Ketoglutarate on Plasma Amino Acid and Hormonal Patterns in Healthy Subjects," J Am Coll Nutr 9.1 (1990) : 2-12.
  
• Cynober, L., et al., "Kinetics and Metabolic Effects of Orally Administered Ornithine Alpha-Ketoglutarate in Healthy Subjects Fed with Standardized Regime," Am J Clin Nutr 39.4 (1984) : 514-9.
  
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• Wernerman, J., et al., "Glutamine and Ornithine-Alpha-Ketoglutarate but Not Branched-Chain Amino Acids Reduce the Loss of Muscle Glutamine After Surgical Trauma," Metabolism 38.S1 (1989) : 63-6.