L-arginine is an amino acid. Amino acids are chemical building blocks necessary for the body to make proteins. L-arginine is naturally found in red meat, poultry, fish, and dairy products

L-arginine is used for the treatment of heart and blood vessel conditions. L-arginine is effective in treating conditions such as congestive heart failure, chest pain, high blood pressure, and coronary artery disease. L-arginine is also effective in the treatment of recurrent leg pain due to blocked arteries (intermittent claudication), senile dementia in the elderly, erectile dysfunction, and male infertility. 

Other use of L-arginine are preventing the common cold, after kidney surgery to improve kidney functions, treating high blood pressure during pregnancy, improving athletic performance, boosting the immune system, and in preventing inflammation of the digestive tract in premature babies. L-arginine is sometimes used in conjunction with other various over-the-counter and prescription medications to treat certain conditions, and is used on wounds on the skin to speed healing.

L-arginine works by being converted in the body into a chemical called nitric oxide. In turn nitric oxide cause the blood vessels to open wider increasing blood flow. L-arginine can be purchased over the counter in capsules, tablets, and liquid forms. Some liquid forms are applied directly to the skin to treat sexual disorders.