Many studies have been done proving the efficacy of testosterone therapy on men, showing that men with low libido have significant improvements to their overall sexual activity, sexual desire, and erectile function. There is emerging evidence demonstrating the benefit of testosterone for women on sexual health as well as general health and wellbeing: One study showed that by age 40, on average a woman's testosterone had declined by one-half. One randomized trial demonstrated 20-50% improvement in wellbeing, mood and sexual function with testosterone treatment in young (premenopausal) women.  Another randomized trial should have 50% increase in satisfactory sexual events for women who were prescribed testosterone support.