Low testosterone in women after 40

Testosterone is also a female hormone

Women produce and use testosterone throughout adult life. Before menopause it comes from the ovaries and the adrenal glands, and part of it is made in the tissues from precursors such as DHEA and androstenedione. The concentration in the blood is much lower than in men, but androgen signalling still matters for sexual desire, muscle, bone and well-being.

What matters clinically is not that every symptom after 40 is caused by low testosterone. Menopausal complaints overlap with sleep problems, thyroid disease, iron deficiency, medication, depression, stress and the relationship with a partner. A good assessment starts with the whole picture, not with a single laboratory number.

What changes with age

Davison and colleagues (JCEM, 2005) measured androgens in 1,423 healthy women aged 18 to 75. Total and free testosterone were highest in the youngest adult group and fell clearly through the 20s and 30s. In other words, much of the decline happened before menopause, not abruptly at it. DHEAS, a precursor from the adrenal glands, also fell steadily with age.

The study did not set a treatment target. It shows why a reference range for women over 40 is not the same as the physiological level of a young woman, and why a number "within normal limits" does not on its own decide whether the symptoms have anything to do with hormones.

Which signs are linked to low testosterone in women?

The sign with the strongest association in studies is persistently reduced sexual desire that the woman herself experiences as a problem. Fatigue, low drive, reduced muscle strength and thinner hair are also often mentioned, but they are non-specific and have many other possible causes. That is why a doctor uses them as part of the conversation, not as proof of a hormone problem. A symptom alone does not show that testosterone is the cause, and a low number alone does not show that it explains the symptoms.

Menopause and the ovaries

After a natural menopause the ovaries continue to produce some testosterone for years. In women who have had both ovaries removed, testosterone falls more markedly and more quickly. That is one reason why surgical menopause often brings clearer changes in desire and energy than a natural transition.

What the test can and cannot tell you

There is no agreed cut-off at which a woman has androgen deficiency based on the number alone. The Endocrine Society guideline on androgen therapy in women (Wierman et al., JCEM 2014) advises against diagnosing "androgen deficiency" in healthy women because of a low number, partly because common assays are imprecise at the low concentrations women have.

A useful test in women is total testosterone, SHBG and calculated free testosterone, preferably measured by mass spectrometry (LC-MS/MS), because immunoassays often miss at low values. Oral oestrogen and some contraceptive pills can raise SHBG and thereby lower the free fraction, even when the total number looks ordinary. You can read more in SHBG and free testosterone.

What the research actually supports

The Global Consensus Position Statement on testosterone for women (Davis et al., 2019), endorsed by several international menopause and endocrine societies, reaches one clear indication: postmenopausal women with persistent, distressing low sexual desire (hypoactive sexual desire disorder), after other causes have been looked into. It builds in part on a meta-analysis by Islam and colleagues (Lancet Diabetes & Endocrinology, 2019), which pooled 36 randomised trials with more than 8,000 women. Testosterone in doses that match women's natural levels gave a modest improvement in desire, arousal and satisfying sexual events.

The consensus statement found insufficient evidence to use testosterone for bone, memory, mood, energy or the heart in women. It is important to say that clearly, because many online sources promise more than the studies show.

Safety and dose

In the trials, the most common side effects were slightly increased hair growth and acne. Serious side effects were rare at doses within the female range, but long-term data over several years are limited. Doses for women are around a tenth of those for men, and a male protocol must never be scaled down "by eye". Monitoring of blood tests and symptoms is part of it.

When does it make sense to test?

It can make sense to measure testosterone and SHBG if, after 40, you have persistently reduced desire that bothers you and other explanations have been reviewed. It can also be relevant after removal of the ovaries, during treatment with oral oestrogen or pills with a strong SHBG effect, or if you have symptoms that also fit other hormone disorders. If your question concerns women under 40, read low testosterone in women before 40.

Next step

Write down your symptoms and how long you have had them. Take a morning sample with total testosterone, SHBG and calculated free testosterone. The first test can be taken locally where you live. The result is not a diagnosis in itself, but a starting point for a conversation with a doctor who looks at the numbers together with your symptoms, your medication and your history. The decision about any treatment belongs to the doctor.