Testosterone was once considered an exclusively male hormone. Men produce 10 to 15 times more than women, but research over the past decade has demonstrated that this hormone also plays a definite role in women's physical and psychological health, particularly their sex drive. Testosterone, which is significantly reduced following surgical or natural menopause, regulates a woman's libido. Heightened libido is not the only benefit of testosterone; many women report that they have more energy and a greater sense of well-being.