Masters and Johnson first proposed a model of sexual function for both men and women in the 1960s. By the mid-1970s, Kaplan modified the model proposed by Masters and Johnson and characterised the female sexual response cycle as a three phase model composed of “desire”, “arousal” and “orgasm”.
Most women with a partner engage in sexual activity, however many who do so do not experience orgasm with sexual activity. ‘Anorgasmia’ – or inability to reach orgasm – is in fact the second most reported sexual problem by women (behind low sexual desire). There is presently no therapy for the condition other than sexual counselling.
It has been reported that about 30 per cent of women cannot achieve orgasm during intercourse. For many women, inability to experience orgasm translates into sexual activity becoming a chore or a duty instead of a shared positive experience.
There are many factors that may contribute to anorgasmia. It may arise from emotional factors, such as relationship issues or past sexual abuse, biological factors including medical problems or side effects of medications, or a combination of these. It may be limited to certain situations or may be an ongoing problem.
Biological factors, including brain chemicals, are integral parts of sexual function and a balance between excitatory brain activity and inhibitory brain activity may be necessary for a healthy sexual response. Sex hormones (oestrogens, androgens and progesterone) all influence a woman’s motivation for or against sexual activity. The role of the androgen testosterone is best understood; it plays a crucial role in sexual desire, arousal and receptivity towards sexual stimulation, and possibly orgasm.
Low androgen testosterone levels may contribute to the development of anorgasmia in women who have previously frequently experienced orgasm. Studies of testosterone therapy for the treatment of low sexual desire in women have indicated that testosterone, taken in a dose appropriate for women, may result in increased ability to reach orgasm. This is because testosterone therapy not only improves sexual desire through central actions in the brain, but also results in increased vaginal blood flow, which is critical for the experience of orgasm.
Thus there is biological justification for exploring the use of testosterone to facilitate orgasm in women. This will be first studied in premenopausal women who have previously been able to experience orgasm, but who have become unable to do so for at least six months, and who are in a stable sexual relationship. The approach to using testosterone for this purpose is novel.
The study, evaluating testosterone for anorgasmia, women will self-administer a dose of testosterone gel or placebo gel, as a tiny droplet, into their nasal passage a couple of hours before they think they might have a sexual encounter. The testosterone will be rapidly absorbed through the nasal lining, resulting in a sudden rise in levels in the circulation. We, and others, have previously shown this to be associated with blood vessel dilation and an associated increase in genital blood flow. Orgasm is potentially facilitated by a combination of central brain effects of testosterone and genital blood flow effects.
Anorgasmia is a frustrating condition for women who have previously enjoyed a satisfying sexual relationship. We have previously shown that women who experience dissatisfying sexual relationships have lower wellbeing in comparison to women who are satisfied with their sexual life. Furthermore, sexual satisfaction in a relationship is a significant determinant of overall relationship satisfaction. For these reasons, among others, this research is a major step forward for the many women who suffer from the condition.
Professor Susan Davis is a leading women’s health researcher and Chair of Women’s Health in Monash University’s Department of Medicine at the Alfred Hospital.