What is AAKG?
AAKG, or Arginine alpha-ketoglutarate, is a salt made up of amino acid arginine, and metabolic intermediate alpha-ketoglutarate. It is a popular supplement, particularly before a workout, because it works in a number of different ways to enhance pump, preserve muscle mass, and boost energy.
Where does AAKG come from?
Both components of AAKG are produced within our own bodies. Arginine is known as a conditionally essential amino acid, which means our bodies are able to produce it in limited amounts, but the main source of arginine is the protein in food, and this amino acid is abundant in meat, dairy, nuts, seeds and wheat.
Alpha-ketoglutarate (AKG) is an intermediate product in the Krebs cycle, which is the metabolic pathway our cells use to generate energy.
AAKG is said to have a variety of benefits, which are best catalogued according to each component. Arginine plays a number of roles in the body. Besides its role as a structural amino acid which the body uses to produce protein, It is a precursor which is acted upon by an enzyme called nitric oxide synthase to produce nitric oxide. This substance stimulates the temporary dilation of blood vessels, increasing blood flow to the muscles (1). As a precursor to urea, which is the form in which excess nitrogen is removed from the body, Arginine also plays an important role in removal of waste.
This amino acid is important for optimum immune function, and it also plays a role in promoting wound healing (2). It is necessary for the production of creatine, and research has shown that arginine interacts with hormones, and supplementation can boost the body's own secretion of growth hormone (3).
AKG is best known as an energy-generating intermediate in the Krebs cycle. One of the ways in which AKG is formed to enter this cycle is through the transamination of glutamate. Glutamate is also a precursor to amino acid glutamine which is required in large amounts, particularly by active people, who are at risk of muscle breakdown to replenish depleted glutamine levels. Therefore AKG supplementation can prevent catabolism by allowing the body to produce more glutamine.
Like arginine, AKG is also a carrier of waste nitrogen, and plays a role in the detoxification of ammonia (4), and it has antioxidant properties (5).
AAKG Benefits for Bodybuilding
These attributes mean that AAKG has many benefits to bodybuilders and athletes.
One of the major reasons AAKG is used is for its vasodilatory effects, or ability to produce a pump. This not only looks and feels good, but the increased blood flow makes sure the working muscle receives abundant oxygen and nutrients and that waste is removed quickly, which means you can work harder for longer.
Because AKG feeds directly into the Krebs cycle, its presence ensures that the muscles have energy during training. The ability of AAKG to shift the body's equilibrium toward glutamine production and away from potentially catabolic muscle breakdown is of large value to people who are building a muscular physique.
AAKG Side Effects, Safety Concerns, Negatives
This is a relatively safe, naturally occurring supplement, but side effects have been noted. These include stomach upset and diarrhoea, and some people may experience dizziness, heart palpitations, and headache, likely as a result of vasodilation. These side effects are most likely to occur with higher doses of the supplement (6).
There have not been a large number of scientifically conducted human trials on AAKG and performance, and the those that have been undertaken vary in their outcome. Some researchers found that supplementation with AAKG afforded no additional benefit to performance (7,8), but others have concluded differently, and there is a great deal of anecdotal evidence supporting the efficacy of AAKG.
AAKG Recommended Dosage & Ingredient Timing
The best time to take AAKG is before a workout, to reap the full benefit of its action. 3-6g of AAKG 30 minutes before a workout is a standard dose for this supplement. AAKG can be taken throughout the day if consistently high arginine levels are desired, but single doses of more than 10g are likely to generate the aforementioned side effects.
AAKG is available as a stand alone supplement, and it is frequently present as an ingredient in pre-workout formulations.
AAKG is best stacked with other ingredients that can be of benefit prior to a workout, including beta alanine, carnitine, BCAAs, and even fast-digesting protein powders.
(1) Andrew PJ, Mayer B. Enzymatic function of nitric oxide synthases. Cardiovasc Res. 1999 Aug 15;43(3):521-31.
(2) Witte MB, Barbul A. Arginine physiology and its implication for wound healing. Wound Repair Regen. 2003 Nov-Dec;11(6):419-23.
(3) Alba-Roth J, Müller OA, Schopohl J, von Werder K. Arginine stimulates growth hormone secretion by suppressing endogenous somatostatin secretion. J Clin Endocrinol Metab. 1988 Dec;67(6):1186-9.
(4) Hares, P; James, IM; Pearson, RM Effect of ornithine alpha ketoglutarate (OAKG) on the response of brain metabolism to hypoxia in the dog.".Stroke; a journal of cerebral circulation (May–Jun 1978). 9 (3): 222–4.
(5) Long, L; Halliwell, B "Artefacts in cell culture: α-Ketoglutarate can scavenge hydrogen peroxide generated by ascorbate and epigallocatechin gallate in cell culture media.". Biochemical and biophysical research communications. (2011) 406 (1): 20–24.
(6) Prosser JM, Majlesi N, Chan GM, Olsen D, Hoffman RS, Nelson LS. Adverse effects associated with arginine alpha-ketoglutarate containing supplements. Hum Exp Toxicol. 2009 May;28(5):259-62.
(7) Willoughby DS, Boucher T, Reid J, Skelton G, Clark M. Effects of 7 days of arginine-alpha-ketoglutarate supplementation on blood flow, plasma L-arginine, nitric oxide metabolites, and asymmetric dimethyl arginine after resistance exercise. Int J Sport Nutr Exerc Metab. 2011 Aug;21(4):291-9.
(8) Greer BK, Jones BT. Acute arginine supplementation fails to improve muscle endurance or affect blood pressure responses to resistance training. J Strength Cond Res. 2011 Jul;25(7):1789-94.