Testosterone deficiency in women

Testosterone (T) is an important component of female sexuality, enhancing interest in initiating sexual activity and response to sexual stimulation. Testosterone is also associated with greater well-being and with reduced anxiety and depression. Clinical and biochemical definitions of T deficiency have not been established; hence, the prevalence of this condition is not known. However, surgically menopausal women are among the populations most likely to experience T deficiency, a syndrome characterized by blunted or diminished motivation; persistent fatigue; decreased sense of personal well-being; sufficient plasma estrogen levels; and low circulating bioavailable T (either a low total T/sex hormone binding globulin (SHBG) ratio or free T in the lower one-third of the female reproductive range); and low libido. Exogenous estrogen, particularly when administered orally, increases SHBG, which, in turn, reduces free T and estradiol (E2). After oophorectomy, levels of T and its precursor, androstenedione, decline by approximately 50%. T replacement continues to be evaluated as an adjunct to estrogen replacement therapy, particularly for women with androgen deficiency symptoms, surgically menopausal women and women with premature ovarian failure. In the United States, oral methyltestosterone is the common product currently approved for androgen replacement in women. The best product specifically designed for women has yet to be determined, as standardized, long-term, randomized, control clinical studies are lacking and product refinement continues.