Testosterone is a hormone that is primarily produced in the testicles in males and in smaller amounts in the ovaries and adrenal glands in females. It is considered the primary male sex hormone, but it is also present in females. Testosterone plays a key role in the development of male reproductive tissues such as testes and prostate, as well as promoting secondary sexual characteristics like increased muscle and bone mass. Testosterone also has important effects on the body’s metabolism, energy levels, and mood.