Women are not as unique as thought by some: Comment on “Hormonal predictors of sexual motivation in natural menstrual cycles”, by Roney and Simmons

Abstract

In female mammals, sexual interest is modulated by estradiol andin many cases progesterone. Even in those species where females usetestosterone (T), such as the musk shrew, T must be aromatized toestradiol to modulate female sexuality (Rissman et al., 1990). Theview concerning hormones and women's sexuality is quite different.The notion that women's sexual desire is modulated not by estradiol,but by testosterone is commonly held and makes women uniqueamong mammalian females. The emphasis on T as the modulator ofwomen's sexual desire has led to the notion of androgen deficiency(Davis, 2001) as an explanation for low sexual desire in women,even though no specific level of testosterone reliably predicts themagnitude of women's sexual desire (Davis et al., 2005). Still, theview of T as the primary modulator of women's sexual desire remainspopular in the face of evidence that testosterone treatment for lowsexualdesireinwomenhaslittleeffect—typicallynotincreasingsexu-al desire significantly above that resulting from placebo treatment(Alexander et al., 2004). These limited effects require concurrent es-trogen therapy (Alexander et al., 2004). In addition, estradiol itselfcan restore sexual desire if given at doses that mimic mid-follicularserum estradiol levels (>100 pg/ml; Alexander et al., 2004). Thus es-tradiol is clearly important for testosterone's therapeutic effect and iscapable of increasing women's sexual desire if given in high physio-logical doses. Evidence of endogenous testosterone or estradiol's in-fluence on women's sexual desire is unclear.Studies of ovarian cycle variation in women's sexual desire, usingthe post-ovulatory rise in basal body temperature to align ovariancycles, showed a striking periovulatory peak in the number of womenreporting increased sexual desire (Stanislaw and Rice, 1988). Thissuggested that changes in ovarian hormones modulated women'ssexual interest but gave no indication of which ovarian hormoneswere important. Waxenberg et al. (1959) had previously argued, onthe basis of a study of the effects of ovariectomy and adrenalectomyon women's sexuality, that ovarian hormones were irrelevant and