Testosterone, also commonly called as the male hormone, is essentially found in males and in much smaller quantities in females. It plays an important role in the growth phase of the male body and is responsible for maturing of male reproductive organs, development of masculine features (facial hair etc.,), distribution of muscle mass and regulation of metabolism. In females, it influences distribution of muscle mass, fat and growth of red blood cells. Excess levels of testosterone is related to development of clots inside the body due to increased amounts of red blood cells. Reduced levels of testosterone can lead to loss of lean muscle mass, erectile dysfunction and low libido.