Citrulline is an amino acid that the body produces constantly. Everyone is supposed to have it. This substance can most commonly be found in the liver. It plays a huge role in how the body processes ammonia. This process is called the urea cycle wherein the toxin, ammonia, is converted into urea with the aid of citrulline before it is then expelled from the body.

While not enough citrulline can cause serious problems, so can too much. Elevated levels have been linked to problems with the central nervous system or CNS, liver and kidneys. There are currently many products on the market containing citrulline. The marketing for these products is toward bodybuilders and sports enthusiasts who want to have en edge on the competition.

The product labels will boast of the ability of citrulline to enhance performance, increase energy and stamina and help people bulk up. However, little to no scientific research has been done to back up this claim. In fact, overdoing it on the citrulline is probably not a good idea anyway. Sometimes, there is such a thing as having too much of a good thing.

An interesting fact is that you cannot obtain citrulline from your diet. No food contains it because it is produced in the liver by other amino acids. In fact, it is merely a stepping stone in the conversion process before citrulline turns into arginine.

Citrulline is detected using bodily fluids in order to measure the level using chromatography. Essentially, the testing method works by separating the various chemicals in the fluids in order to isolate citrulline and measure the levels found.

One good thing to note is that some studies are beginning to show that citrulline may be able to help improve mental function, especially in those who suffer from Alzheimer's Disease. It may also play a role in reducing fatigue. Now these are the kinds of studies that could change everything!

The idea of having too much citrulline is not to be confused with the build up of the substance in the body due to an inability to process it and an inability for it to process ammonia. That is called citrullinemia