Testosterone is a hormone, a molecular messenger that travels through your bloodstream to act on many organs and tissues in your body, including your brain, muscles, fat, bones and sexual organs.
Testosterone and the brain
Your thinking abilities and general sense of well-being, including your mood, energy level and sense of vitality, and sexual drive or libido are all affected by testosterone.
Testosterone and muscle
Testosterone creates muscle cells and causes them to grow in size and strength.
Testosterone and fat
Testosterone has been shown to reduce body fat, particularly in the midsection and chest. The result is an improvement in lean body mass.
Testosterone and bones
Testosterone helps prevent the normal bone destruction of aging and actually improves bone density. This reduces the risk of osteoporosis and fractures.
Testosterone and the heart
Testosterone can inﬂuence cardiovascular risk factors indirectly through its effect on the amount of fat in your body, and there is evidence it benefits the heart directly. It may help open the coronary arteries, and possibly improve cardiac function in people with heart disease and heart failure.
Testosterone and sex
Low testosterone can reduce your ability to have satisfying sex. Lack of sex drive and erectile dysfunction are sexual problems that can result from low testosterone. If low testosterone is the cause, treating it can help.