@rn.naalamiley: What does testosterone do? Testosterone is important in the development of the male reproductive organs, such as the testicles and penis. It is responsible for the changes during puberty in males, such as ⚫ body hair ⚫ a deeper voice ⚫ stronger muscles ⚫ growth spurts ⚫ penis growth ⚫ acne In adult males, testosterone carries out important body functions, such as ⚫ regulating sex drive and mood ⚫ regulating bone and muscle strength making new blood cells ⚫ helping the testes make sperm In females, testosterone is needed for bone and muscle strength and sex drive. Some of it is converted to a form of oestrogen. What causes low testosterone? Your body needs to maintain normal levels of testosterone for it to function properly. Testosterone levels are controlled by a feedback loop between your brain, your pituitary gland and your testes. Sometimes your body can't make enough testosterone. This could be because your testes are not working properly, or because the pituitary gland in your brain is not telling your testes to make testosterone. A low testosterone level is also known as androgen deficiency or hypogonadism. #