Social media trends promoting testosterone as a vital component of menopausal hormone therapy (MHT) are not supported by scientific understanding of how the hormone functions in women, according to new research. While estrogen levels demonstrably decline during menopause, leading to common symptoms like hot flashes and vaginal dryness, testosterone levels in women decrease with age, not as a direct result of ceasing menstruation.
The misconception, fueled by online discussions and a desire for comprehensive symptom relief, has led some women to believe they are missing out on a crucial aspect of MHT if testosterone isn’t prescribed. Researchers at Monash University in Australia have spent decades investigating the relationship between testosterone and women’s reproductive stages, publishing findings that challenge the prevailing narrative.
Early studies attempting to measure testosterone levels in women were hampered by limitations in testing technology. A 2005 study of 1,400 women, led by researchers at Monash University, indicated that testosterone levels did not change at menopause but gradually declined starting around age 20. A smaller 2000 study of 172 women yielded similar results. However, the accuracy of these earlier findings was questioned due to the inability of available chemical tests to reliably measure low levels of testosterone in women.
More recent advancements in testing methodologies have provided clearer insights. A 2019 study involving 588 women, utilizing these “gold-standard” methods, revealed an average decline of approximately 25% in testosterone levels between the ages of 18 and 39. Building on this work, a new study, published in the journal eBioMedicine, examined the blood testosterone levels of 1,104 participants aged 40 to 69. Researchers meticulously collected menstrual cycle information to categorize participants as pre-menopausal, perimenopausal, or postmenopausal.
The study excluded women taking medications that could affect hormone levels, as well as those with factors known to influence testosterone, such as high body mass index (BMI) or cigarette smoking. Results showed an average decline of 25% in testosterone levels between the ages of 40 and 58-59, with no significant differences observed between the three menopausal stages. However, postmenopausal women who had undergone surgical removal of both ovaries exhibited lower testosterone levels compared to those retaining at least one ovary, confirming the ovaries continue to contribute to testosterone production even after menopause.
Interestingly, the research team observed a slight increase in testosterone levels after age 58-59, mirroring findings from their 2005 study which indicated testosterone levels bottomed out around age 62 before gradually rising. Researchers emphasize that these are average trends, and individual experiences may vary.
Combining data from past and current studies, researchers have constructed a comprehensive picture of testosterone fluctuations throughout a woman’s life. Testosterone levels generally decrease by about 50% from age 20 to age 60, then begin a subtle increase, continuing into the eighth and ninth decades of life. The reasons behind these changes remain unclear.
Current research does not support a direct link between low testosterone and symptoms commonly attributed to deficiency, such as decreased sexual desire, reduced muscle mass, or low mood. However, the gradual increase in testosterone with age may contribute to age-related hair thinning and facial hair growth in some women.
The concept of “testosterone deficiency syndrome” in menopausal women emerged over two decades ago, prior to a thorough understanding of testosterone’s lifecycle in women and robust studies examining its relationship to specific symptoms. Clinical trials have demonstrated that testosterone treatment can modestly improve sexual desire in postmenopausal women experiencing a bothersome decline, but there is currently no consistent evidence to support its use for other menopausal symptoms.
International clinical guidelines currently recommend testosterone therapy only for addressing low sexual desire in postmenopausal women. Researchers are continuing to investigate the effects of testosterone on muscle function and bone density, with findings expected later this year. The Food and Drug Administration (FDA) recently convened an expert panel to review hormone replacement therapy for women, signaling ongoing scrutiny of treatment approaches.
