Testosterone treatment can significantly improve sexual desire, function, and pleasure in postmenopausal women, finds a comprehensive systematic review* and pooled data analysis of the available evidence, and published in The Lancet Diabetes & Endocrinology.
But formulations other than tablets are preferable because of the adverse effects on cholesterol, say the researchers.
Although best known as a male hormone, testosterone is important for female sexual health, contributing to libido and orgasm as well as helping to maintain normal metabolic function, muscle strength, cognitive function and mood. But levels decline naturally over a woman’s lifespan.
Previous research suggests that testosterone therapy can improve sexual function in women, but the available formulations have been designed for men and there’s little evidence on their safety or side effects in women.
“Our results suggest it is time to develop testosterone treatment tailored to postmenopausal women rather than treating them with higher concentrations formulated for men,” says senior author Professor Susan Davis from Monash University, Australia.
“Nearly a third of women experience low sexual desire at midlife, with associated distress, but no approved testosterone formulation or product exists for them in any country and there are no internationally-agreed guidelines for testosterone use by women. Considering the benefits we found for women’s sex lives and personal wellbeing, new guidelines and new formulations are urgently needed.”
The authors reviewed 46 reports about 36 randomised controlled trials, conducted between January 1990 and December 2018 and involving 8,480 women between the ages of 18 and 75, most (95%) of whom were postmenopausal.
The trials compared testosterone treatment to a placebo or to an alternative hormone treatment such as oestrogen, with or without progestogen.
The authors reviewed the effects of the treatments on sexual function and on measures of heart, cognitive, and musculoskeletal health. They looked for serious side effects such as increased risk of heart disease or breast cancer, as well as the impact on mood and wellbeing, and other measures of breast health, such as breast tissue density, metabolic effects, lipid profiles, as well as “maleness”, including increased hair growth.
In 15 studies involving 3,766 naturally and surgically postmenopausal women, consistent beneficial effects were seen for all measures of sexual function. Testosterone treatment was associated with an increase in the frequency of satisfactory sex. And it significantly increased desire, pleasure, arousal, orgasm, responsiveness to sexual stimuli and self-image.
The hormone treatment was also associated with fewer sexual concerns and lower sexually-associated distress.
“The beneficial effects for postmenopausal women shown in our study extend beyond simply increasing the number of times a month they have sex,” says Professor Davis.
“Some women who have regular sexual encounters report dissatisfaction with their sexual function, so increasing their frequency of a positive sexual experience from never, or occasionally, to once or twice a month can improve self-image and reduce sexual concerns, and may improve overall wellbeing.”
But testosterone treatment was not associated with improvements in cognitive function, bone mineral density, body composition or muscle strength. Nor was it associated with improvements in low mood, irrespective of menopausal status, or in psychological wellbeing. But the number of women included in these studies was small, caution the authors.
No serious side effects on glucose or insulin levels, blood pressure, or measures of breast health were recorded. But only limited data were available for breast cancer risk.
While no effects on lipid profiles or metabolic variables were evident (10 studies involving 1774 women) for formulations other than tablets, oral formulations were associated with increased LDL cholesterol and reduced HDL cholesterol, overall cholesterol and triglycerides. But postmenopausal women were also no more likely to have a heart attack or stroke (nine clinical trials with 4,063 women).
Acne and increased hair growth were more likely after testosterone treatment, but the number of participants who withdrew from clinical trials as a result was no greater than it was for those treated with placebo, suggesting the effects are mild and not a major concern, say the authors.
Five studies involving 2,032 participants indicated that testosterone treatment was associated with some weight gain.
In a linked comment**, Dr Rossella Nappi from the University of Pavia, Italy, says that further long-term studies are needed to assess the potentially therapeutic role of testosterone for women in healthy ageing.
“In particular, there is an urgent need in the area of sexual medicine to ensure gender equality in treating effectively those women with female sexual dysfunction clearly related to hypoandrogenic states. However, products specifically approved in women should become available to achieve this goal.”
*Islam RM, Bell RJ, Green S, et al. Safety and efficacy of testosterone for women: a systematic review and meta analysis of randomised controlled trial data.The Lancet Diabetes & Endocrinology, 25 July 2019. DOI: 10.1016/S2213-8587(19)30189-5
**Nappie RE. Testosterone for women: green light for sex, amber light for health?. The Lancet, 25 July 2019. DOI:10.1016/S2213-8587(19)30251-7