Does my libido decline after 40, and is there anything I can do about it?

A decline in libido after the age of forty is a real and common phenomenon for both men and women. In women, the ovaries play a central role: around menopause they gradually stop producing oestrogen and testosterone. Up to half of sexually active older women report a bothersome sexual problem, with reduced desire being the most common. Added to this, falling oestrogen levels can cause vaginal dryness (known as genitourinary syndrome), which can make sex painful or uncomfortable. Even so, a majority of older women continue to consider sex important in their lives.

In men, testosterone declines gradually with age, a process sometimes referred to as late-onset hypogonadism. Approximately 30% of men between the ages of 40 and 79 have a measurable testosterone deficiency, which can be accompanied by reduced libido, erectile problems, muscle loss, increased abdominal fat, and fatigue. Obesity, diabetes, and high blood pressure increase the likelihood of this occurring. It is therefore not an inevitable fate for everyone, but it does affect a considerable minority.

For men in whom both symptoms and a clinically measured low testosterone level have been established, testosterone therapy (TRT) is an option supported by solid evidence. A large randomised study (the TRAVERSE trial, over 1,100 participants) showed that TRT significantly improved sexual activity and desire, an effect that remained demonstrable up to two years after the start of treatment. An important caveat: for erectile problems, TRT did not help in that study. Furthermore, TRT is only meaningful in the combined picture of symptoms and a demonstrably low testosterone level; it does not work as a general anti-ageing remedy for men with normal values.

For women around menopause, hormone therapy and lifestyle adjustments are available options. Hormone therapy is described as effective for sexual complaints associated with the decline in reproductive hormones. The treatment of vaginal dryness and pain during intercourse is a concrete, well-supported application within this. Non-hormonal and non-medical approaches are also mentioned, but exact effect sizes were not specified in the available studies.

DHEA is a hormone precursor that the body converts into oestrogen and testosterone, and it declines sharply with age. There are indications that supplementation in women over 70 may have a limited positive effect on libido, but research findings are contradictory. The long-term risks for cardiovascular disease and hormone-dependent cancers have not been sufficiently studied; the researchers who have examined this therefore explicitly advise against DHEA supplementation for older adults. Finally, a practical note for men who use dutasteride or finasteride for hair loss: both medications can reduce libido as a side effect by influencing testosterone metabolism. This is worth keeping in mind if you develop complaints about reduced desire after forty while using one of these medications.