Arginine vs. Agmatine

Fact Checked

iStockbyte/Stockbyte/Getty Images

Arginine is an amino acid used to build muscle and body tissue, and it is also used for biochemical reactions in your body. One unique function of arginine is to act as a raw material for your body to produce nitric oxide, or NO. This gas is important for maintaining blood vessel tone and dilating blood vessels in response to increased oxygen demand. Agmatine is a metabolite of arginine, a chemical produced from arginine by biochemical reactions in your body. Neither arginine nor agmatine is a substitute for medical care or the medication prescribed by your doctor.

Nitric Oxide

Though many cells in your body produce NO as a biochemical signal, the regulation of blood flow by the vascular endothelium—the cells that line your blood vessels—is the primary use of NO by your body. Your blood vessels produce a steady supply of NO from the amino acid arginine, but they can produce a much larger amount in response to oxygen demand. Poor production of NO due to a low-protein diet or cardiovascular disease can substantially impair blood flow.


Arginine is a conditionally essential amino acid, meaning that although healthy individuals can produce sufficient amounts, some people may require arginine from foods or supplements. Two groups of note are those undergoing intense physical training and those suffering from cardiovascular disease. Arginine is also involved in wound healing and recovery from injury.


Agmatine is thought to act as a neurotransmitter, a chemical that modulates the activity of cells in your brain. Agmatine is an intermediate product in the synthesis of polyamines, an important chemical for cell growth. Agmatine can also inhibit the production of NO from arginine by inhibiting the enzyme NO synthetase. Because of the production of agmatine and other compounds, the effects of arginine on NO synthesis and blood vessel dilation is limited naturally by your body.


Arginine has shown some promise in the treatment of growth hormone disorders, heart disease, heart failure and peripheral vascular disease, according to Although preliminary research has shown promise in other areas, such as circulation, athletic performance, and the treatment of critical illness, further research is needed in those areas. Few research trials have investigated the effects of agmatine supplementation. Some athletic performance supplements include agmatine with arginine, as the extra agmatine inhibits further conversion of arginine to agmatine, increasing the amount of arginine converted to NO.


Arginine and agmatine are produced naturally by your body, and they are likely safe when taken by healthy individuals in moderate amounts. However, the complete effects of arginine and agmatine as refined supplements are not known. Consult with your healthcare provider before taking either as a supplement if you are currently under medical care or are taking prescription or over-the-counter medication. Supplements may cause allergic reactions; seek medical care if you experience shortness of breath, burning, rash or itching. The maximum recommended daily intake of arginine is 6,000 milligrams, according to