Testosterone is the primary hormone behind muscle-building, fat-burning, libido, and even strongly affects mood and energy. The testicles are the main source of testosterone production in men while the ovaries are in charge of producing this sex hormone in women. However, in women, levels of testosterone are typically lower compared to men. However, abnormally low testosterone levels in women (as well as men) can contribute to symptoms and may indicate an underlying health issue. In general, men begin to experience an increase in testosterone production during puberty, with testosterone levels gradually declining starting at about age 30. When natural testosterone levels begin to lower, both men and women can experience a number of different symptoms.
