Detailed definition
Testosterone is the principal androgen in both sexes. In women it is produced in roughly equal amounts by the ovaries and adrenal glands, with circulating total testosterone in premenopausal women typically 15–70 ng/dL — about one-tenth to one-twentieth of male levels. Testosterone is partly converted to estradiol by aromatase and partly to dihydrotestosterone by 5α-reductase. In women it contributes to libido, energy, lean muscle mass, and bone density, and it appears to influence mood and cognition. Ovarian testosterone production declines with age, and women who undergo bilateral oophorectomy lose roughly half their circulating testosterone overnight. The Global Consensus Position Statement on the Use of Testosterone Therapy for Women (2019) concluded that the only evidence-based indication for testosterone therapy in women is postmenopausal hypoactive sexual desire disorder (HSDD). The FDA has not approved a female testosterone product, so US prescribers typically use a small fraction of a male transdermal product or a compounded formulation, dosed to keep total testosterone within the female physiologic range.
Why it matters in menopause
Many women hear testosterone marketed as the answer to fatigue, weight gain, brain fog, and mood — but the evidence for those uses is weak or absent. The single use with strong evidence is libido restoration after menopause when low desire is causing distress. Pellet testosterone marketing routinely produces supraphysiologic levels (5–10× normal female range) with no proven benefit and side effects including acne, facial hair, voice change, and clitoral enlargement.