In the world of social media public opinion, testosterone is the ‘hormone du jour’.

Proponents, many of whom are popular doctors with large followings from across the globe, say it’s the third leg in the menopause hormone therapy (MHT) stool and a must-have for all those going through menopause. They claim it can prevent heart disease, fix a flat-lined libido and transform the fatigued, depressed, brain-fogged and cognitively challenged menopausal woman back to her previously well-functioning self. And there’s a chorus of patients who gladly flex their fingers to attest to its efficacy, claiming on social media posts and in chat groups that it’s ‘the icing’ on their hormone replacement cake and they couldn’t cope without it.

But what does the evidence say, and what can you tell your patients if they think testosterone is the hormone for them?

Professor Susan Davis, a leading researcher on testosterone in menopause and Head of the Monash University Women’s Health Research Program, says many of the claims are little more than ‘hot air’.

“There’s too much embellishment and hyperbole about benefits that have never been established and I think we should be honest with women and say ‘this is the data,” she said in an interview with the Menopause Research and Education Fund.

No matter how compelling the anecdotes on the benefits of testosterone, the only solid evidence is for the treatment of Hypoactive Sexual Desire Disorder (HSDD).

According to the International Menopause Society (IMS), which dedicated the 2024 World Menopause Day to MHT and issued a White Paper that aims to unravel the misinformation, testosterone therapy may improve HSDD in postmenopausal women both using and not using menopausal hormone therapy. However, estrogen deficiency symptoms, including vaginal dryness, should be treated before a trial of testosterone therapy.

The paper adds: “The global consensus statement on testosterone for women recommends following a biopsychosocial approach in deciding whether prescribing testosterone is indicated.” The recently released revised NICE guidelines on menopause only recommend testosterone for low libido if MHT alone is not effective.

Setting realistic patient expectations

HSDD is complex and multifaceted, and testosterone is not always a silver bullet. According to UNSW Conjoint Associate Professor John Eden, a gynaecologist and reproductive endocrinologist, around one third of women don’t respond to testosterone treatment for low libido and when it does work, it can be a ‘slow burn’ taking 4-6 weeks to start to see a difference.

Professor Davis agrees, adding that the placebo effect with testosterone treatment is huge. In a double-blind study she worked on, “when we unblinded the study some women who had been on placebo had massive improvements in sexual function. It was mind blowing improvements.”

But, the placebo effect usually wains over time, she says. She suggests trialling testosterone for up to 6 months with patients to see if it makes a difference.

Does the testosterone level matter?

No, is the simple answer. Professor Davis says regular lab tests are not sufficiently sensitive to be meaningful with such small levels in the blood, but blood levels should be monitored to ensure patients are not reaching supraphysiological levels before they exhibit side effects such as increased acne, hirsutism, a permanently lowered voice, or clitoromegaly. (The general recommendation is levels should not be more than 50% above the upper limit of the premenopausal reference range of the laboratory where the testosterone is measured).

Professor Davis says some patients may have no libido issues with ‘testosterone levels in their boots’ while others with higher levels may have low libido, so it’s the symptom that’s important, not the blood level.

What about the other claims?

When it comes to claims beyond low libido, the water gets murky. There are studies that show pros and cons in many areas, but when it comes to meta-analysis the evidence falls short.

Let’s take them one by one.

1. Misconception #1: ‘Testosterone can prevent heart disease.’

Claims that women with lower levels of testosterone have a higher risk of a major adverse cardiovascular event come from the misinterpretation of a study co-authored by Professor Davis in 2022. It found women in their 70s with lower levels of either testosterone or DHEA had a higher risk of a cardiovascular event. The conclusion was that “in healthy women from Australia aged 70 years and older, having blood testosterone or DHEA concentrations above the lowest quartile appears to be cardioprotective. Replication of these findings would justify the consideration of trials investigating testosterone therapy for the primary prevention of ischaemic cardiovascular disease events in older women with low circulating concentrations of testosterone.”

This, Professor Davis says, is a far cry from saying testosterone can prevent heart disease in younger women or that it should be given to women going through menopause as a preventative measure.

“The logic is flawed,” she says.

Yes, the women with the lowest testosterone had the highest risk but “that doesn’t mean the low testosterone is the cause or that giving testosterone will prevent anything. It may be a biological marker of worse health because once you are postmenopausal your testosterone comes from adrenal glands … so it may be a marker of adrenal function or the cell machinery and have nothing to do with blood testosterone levels.”

“To go around telling 50-year-olds to take it to prevent heart disease is completely inappropriate.”

2. Misconception #2 ‘Testosterone will improve cognition and prevent dementia.’

Support for this claim is based on a variety of things including:

• That men have less dementia than women
• Anecdotal claims of brain fog clearing with testosterone use.

But, when it comes to hard evidence the stats don’t stack up, Prof. Davis says. She says one of her RCTs of 100 women showed a borderline statistical improvement in verbal memory but there was no dramatic improvement in any other aspects.

“Our published research shows there is no difference in cognitive function in older women in relation to blood test levels and we showed no difference in brain aging in relation to testosterone levels. At this stage, we have not been able to demonstrate meaningful cognitive benefits. We’ve reviewed the entire literature base systematically and there is no consistent evidence of benefit. More research is needed.”

3. Misconception #3: ‘Testosterone will build stronger muscles and bones’

Again, it’s a ‘no’. Claims on this stem from a small study on 15 gender-transitioning women using pellets and as the study itself says, may be attributed to the aromatization of testosterone to oestradiol. More studies are underway but at the moment, Prof. Davis says meta-analysis shows no improvement in muscle or fracture prevention.

4. Misconception #4: ‘Testosterone can be used as an anti-depressant’

Small studies (here and here), summarised in the introduction here, suggested low-dose testosterone could improve low mood in women without diagnosed clinical depression, but these findings were not confirmed in larger more recent studies. The available data does not support a benefit of testosterone on low mood or depressive symptoms over placebo therapy.

“It’s really not going to treat those things and [patients] should be having appropriate therapy,” Professor Davis says.

Does this mean it’s the end of the story? No, more research is needed and some is underway, but until those results are in Professor Davis says it’s best to err on the side of caution.

“My belief is that if I think women might benefit from testosterone for all these things, I should study these outcomes in a clinical trial that’s properly designed, and not do a human experiment in the community at potentially women’s expense.”