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.
- 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:
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.
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.
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.
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.
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
- 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.
- Cynober, L., "Ornithine Alpha-Ketoglutarate in Nutritional Support," Nutrition 7.5 (1991) : 313-22.
- Donati, L., et al., "Nutritional and Clinical Efficacy of Ornithine Alpha-Ketoglutarate in Severe Burn Patients," Clin Nutr 18.5 (1999) : 307-11.
- Jeevanandam, M., et al., " Ornithine Alpha-Ketoglutarate (OKG) Supplementation Is More Effective than its Component Salts in Traumatized Rats," J Nutr 126.9 (1996) : 2141-50.
- Le Boucher, J., and Cynober, L.A., "Ornithine Alpha-Ketoglutarate: The Puzzle," Nutrition 14 (1998) : 303-6.
- Moukarzel, A.A., et al., "Growth Retardation in Children Receiving Long-Term Parental Nutrition: Effects of Ornithine Alpha-Ketoglutarate," Am J Clin Nutr 60.3 (1994) : 408-13.
- Vaubourdolle, M., et al., "Influence of Enterally Administered Ornithine Alpha-Ketoglutarate on Hormonal Patterns in Burn Patients," Burns Incl Therm Inj 13.5 (1987) : 349-56.
- 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.