It is produced in the [[testes]] in men , and in the [[ovaries]] in women. Men typically have higher levels than women. Testosterone is involved in muscle development, bone growth and production of red blood cells. It also is involved in development of body and facial hair. Levels of this hormone may decrease with age, and will decrease as a result of damage to or loss of the testes due to injury, illness or medical treatments such as [[chemotherapy]] or radiation. | It is produced in the [[testes]] in men , and in the [[ovaries]] in women. Men typically have higher levels than women. Testosterone is involved in muscle development, bone growth and production of red blood cells. It also is involved in development of body and facial hair. Levels of this hormone may decrease with age, and will decrease as a result of damage to or loss of the testes due to injury, illness or medical treatments such as [[chemotherapy]] or radiation. |