Testosterone in Women: The Overlooked Hormone That Changes Everything

Testosterone is not just a male hormone. Women produce it throughout their lives — and its decline during perimenopause has wide-ranging effects on energy, cognition, and libido that are almost never discussed.

Of all the hormones involved in the perimenopause transition, testosterone receives the least attention — both in clinical practice and in public discussion. Oestrogen decline drives most of the most visible symptoms, and rightly dominates perimenopause conversations. But testosterone's decline has effects that are significant, wide-ranging, and that often persist even when oestrogen is adequately replaced by HRT — because testosterone's role is distinct, and replacing oestrogen does not automatically address testosterone deficiency.

What Testosterone Does in Women

Women produce testosterone in the ovaries and adrenal glands throughout their lives, in amounts approximately ten times lower than men but physiologically significant. Testosterone acts on androgen receptors throughout the body — in the brain, muscle tissue, bone, cardiovascular system, and sexual response tissues.

In the brain, testosterone affects processing speed, mental sharpness, and cognitive drive — the motivated, alert quality of engaged thinking. It influences the dopamine system in ways that affect reward processing, motivation, and the ability to find activities engaging and pleasurable. It contributes to confidence and risk tolerance. Many women describe its decline as becoming progressively "dimmed" — still functioning, but at reduced intensity. Less drive, less pleasure in activities that previously felt rewarding, less mental sharpness than before.

In muscle tissue, testosterone regulates protein synthesis efficiency. As it declines during perimenopause, muscle protein synthesis becomes less efficient — the same resistance training that produced clear muscle maintenance pre-perimenopause becomes less effective at preventing muscle loss. Women notice this as reduced responsiveness to exercise, gradual softening of muscle tone despite maintained effort.

In sexual response, testosterone drives desire — both spontaneous wanting and the arousal response to sexual stimulus. It affects genital blood flow and sensitivity. Women with low testosterone frequently report a qualitative change in their sexual experience — a flatness or absence of the pleasurable engagement that previously characterised intimacy — alongside reduced frequency of desire.

How Testosterone Declines During Perimenopause

Testosterone levels in women decline more gradually than oestrogen — typically over decades rather than years, beginning in the late 30s and continuing through perimenopause and postmenopause. This gradual decline means symptoms often develop slowly without a clear moment of onset, and are therefore particularly likely to be attributed to depression, burnout, or relationship dissatisfaction rather than identified as hormonal.

Blood testing for testosterone in women requires female-specific reference ranges — standard laboratory ranges calibrated for men are inappropriate, and "normal" by male standards would represent supraphysiological levels in women. Results should be interpreted alongside symptoms rather than in isolation, since the relationship between blood levels and symptom experience is not perfectly linear.

Testosterone Therapy for Women — The Evidence

Testosterone therapy for women is licensed in the UK for hypoactive sexual desire disorder — low sexual desire causing distress. It is widely used off-label for energy, brain fog, mood, and muscle maintenance. It is prescribed as a gel or cream applied to the skin and requires monitoring of blood testosterone levels. The Global Consensus Position Statement on the Use of Testosterone Therapy in Women (2019), signed by multiple major international societies, provides a clear framework for evidence-based prescribing. Most women notice effects within four to twelve weeks, with energy and cognitive sharpness often among the first improvements reported.

Despite being licensed and supported by major professional bodies, testosterone for women is significantly under-prescribed in NHS primary care. Many GPs are unfamiliar with female dosing, which differs substantially from male dosing. Specialist menopause clinics have considerably higher familiarity and are more likely to discuss it proactively.

If you are experiencing low libido, reduced energy, brain fog, or diminished motivation — particularly if you are already on oestrogen HRT but find these symptoms persist — testosterone is worth discussing specifically: "I've been reading about testosterone therapy for women — I'm experiencing symptoms consistent with testosterone deficiency and I'd like to explore whether it would be appropriate for me."