L-arginine is the natural form of arginine that is found in food, although manufacturers are capable of synthesizing it to produce L-arginine dietary supplements. On the other hand, L-arginine alpha-ketoglutarate or AAKG, is a nonessential amino acid that plays a crucial role in making nitric oxide in the liver. It is also manufactured as a complex dietary supplement containing alpha-ketoglutarate which is a salt derived from glutaric acid.
L-Arginine is regarded as a semi-essential amino acid, because while the body normally produces sufficient amounts of it, supplementation is sometimes required. The body uses L-arginine to synthesize proteins, enzymes and biochemicals like creatine. It is also used by cells lining the blood vessels to produce nitric oxide and stimulate vasodilation, thereby increasing blood flow. Although a small quantity of nitric oxide is constantly produced, its levels can rise by as much as a thousand fold in order to boost oxygen and nutrient delivery throughout the body.
Alpha-ketoglutarate serves as an intermediate in the citric acid cycle, which is the body’s primary means of producing energy and raw materials. AKG ingested as a supplement enters the citric acid cycle, producing energy or other products like L-glutamine which is a major component of muscles. L-arginine alpha-ketoglutarate or AAKG combines the benefits of both substances. It breaks down in the intestines into AKG and L-arginine and is essentially the same as taking both separately.
Physicians prescribe L-arginine supplements for the treatment of cardiovascular disorders like angina, hypertension and congestive heart failure. It has likewise garnered widespread attention for its use in treating patients suffering from impotence (i.e. erectile dysfunction), cataract, type 2 diabetes and peripheral blood flow problems like intermittent claudication.
AAKG is less commonly used for clinical purposes, as manufacturers prefer to market the supplement to athletes, specifically bodybuilders and weightlifters. AAKG can increase short term nitric oxide levels which results in a muscle growth environment in the body. This is achieved by increasing the rate of blood flow to working muscles, which in turn leads to increased glucose uptake, oxygen and nutrient delivery, power output and muscle velocity. AAKG also amplifies muscle-growth signals for faster gains in lean mass and to accelerate both fast and slow twitch muscle fibers for greater strength and increased endurance.
In addition, L-Arginine prods the production of growth hormone or somatotropin, a chemical produced by the anterior pituitary gland that promotes growth and plays an integral role in metabolism. Growth hormone is popular among athletes because it helps in building lean muscle mass and increasing strength. When used in conjunction with your fitness program, AAKG can support myodilation or the expansion of muscle tissue.
Another benefit of AAKG is its function as a precursor in the production of creatine and glutamine. Daily AAKG supplementation has been shown to increase the creatine and glutamine stores of the body. This may result to improvements in strength, stamina and recovery times. Some athletes take alpha-ketoglutarate to improve peak performance because it helps the liver in breaking down the by-products of muscle exercise like ammonia.
L-arginine is most effective when used to increase the levels of nitric oxide for the treatment of congestive heart failure. Its efficacy is supported by three small double-blind, placebo-controlled studies. As for AAKG, supplementation has been extensively researched in different laboratory settings. A study conducted in 2006 and published in the “Nutrition” journal revealed that trained men taking AAKG managed to increase their one-repetition maximum (1RM) for bench press after two months. However, the validity of the result has been questioned because the men did not show any increases in aerobic capacity and body mass to accompany the reported strength gains.
It may well be that AAKG supplements are more impressive when integrated into an overall amino acid supplement to increase blood flow and help build muscle. What is certain is that there is a significant increase in nitric oxide synthesis whenever arginine is released into the bloodstream. When more nitric oxide is present, enhanced work capacity, extended muscle pumps and improved recovery times are more likely.
There is no standard dose for L-arginine. Studies have utilized various quantities for different conditions. A common dosage is 2 to 3 grams taken three times per day, but higher and lower doses have also been tested. Those with burns, infections, protein malnutrition, rapid growth, and other conditions may require supplemental arginine.
L-Arginine alpha-ketoglutarate supplements are sold in pills, tablets or powder. The recommended dosage is 2 or 3 tablets taken once or twice a day on an empty stomach. Most physicians suggest taking the tablets in the morning and at least half an hour before workouts. In powder form, the recommended dose for AAKG ranges from 1500 to 3500 milligrams. Experts believe that it is more beneficial to mix the powder with creatine-based products.
L-arginine is considered safe to take since it is the natural form of arginine that you can normally obtain in foods like dairy products, meat and poultry. According to experts from New York University, most people can tolerate arginine in doses of up to 20 grams per day. However, L-arginine supplements may stimulate acid production in the stomach, alter potassium levels and interfere with herpes treatment. Moreover, due to potential alterations in blood flow or pressure, it is imperative that you only take L-arginine supplements with your physician’s supervision, especially if you are pregnant or have cardiac, renal or endocrine disorder. Rare but serious side effects that required hospitalization have been reported in a very small number of people. Seek immediate medical attention if you experience allergic reactions, bleeding, persistent headache, or changes in vision.
AAKG supplements are also generally regarded as safe to take, though some have been found to contain additives and contaminants. According to registered dietitian Ellen Coleman, in most cases such contaminants are the consequence of poor manufacturing processes, but there are instances when they are deliberately adulterated with chemicals such as anabolic steroids to boost the performance of the product. Again, it is always advisable to seek your physician’s advice before starting L-arginine and AAKG supplementation.