Testosterone (T) is the primary male sex hormone and an anabolic steroid. 

In male humans, testosterone plays a key role in the development of male reproductive tissues such as testes and prostate, as well as promoting secondary sexual characteristics such as increased muscle and bone mass, and the growth of body hair.

In addition, testosterone is involved in health and well-being,

Impact of low testosterone levels

Low levels of testosterone can produce a variety of symptoms in men, including:

• decreased sex drive
• less energy
• weight gain
• feelings of depression
• moodiness
• low self-esteem
• less body hair
• thinner bones