Nitric oxide is a free form gas produced by the body in order to communicate with other cells. It is created when enzymes break down the amino acid arginine. The main benefit of nitric oxide is its role in controlling the circulation of blood and regulating activities of the brain, lungs, liver, stomach and other organs. It also helps in the control of blood pressure, dilates blood vessels to cause penile erection and is used by the immune system to fight viral, bacterial and parasitic infections.

It is the ability of nitric oxide to increase blood flow that is of most interest to bodybuilders who can benefit as follows:

1. The increased blood flow delivers more nutrients to the muscle cells thus helping them to grow during the adaptation and recovery phase.
2. Its ability to reduce inflammation helps muscles that have been subjected to extreme stresses.

Given its close relationship with arginine care should be taken in applying small doses and increasing them gradually until an optimum level is reached. Bear in mind that many protein powders and other supplements are fortified with amino acids so check the labels carefully. The manufacturer's instructions should be followed in all instances.