New study: testosterone therapy in women was linked to improvements beyond libido

A new 2026 study in the Journal of Personalized Medicine followed 332 women receiving individualized, biomarker-guided testosterone replacement therapy as part of routine clinical care. The question: is testosterone therapy linked only to sexual function, or to broader symptoms too — fatigue, mood, memory, concentration, irritability, anhedonia, relationship satisfaction and quality of life?

The strongest signal wasn't libido. It was energy and fatigue — improving in 84.3% of women, the highest result across all eight symptom domains.

Energy led the results, not libido

When asked to name their single biggest area of improvement, women chose energy/fatigue most often (64.2%). Mood came next at 49.7%, followed by sexual desire at 41.3%.

Improvement by symptom

Source: Elggren et al., Journal of Personalized Medicine, 2026 (n = 332).

Mood improved for most participants

Depression improved in 70.8%, irritability in 69.0%, anhedonia in 67.5% and sexual interest in 66.9%. That matters: women's testosterone research is usually framed around sexual desire, but here the reported changes were much broader.

Brain fog improved — but more slowly

Concentration improved in 57.8% and memory in 54.5%. Cognitive gains showed up later than energy or mood — meaningful changes emerged around 4–6 months and continued through 7–12 months. Cognition was not the fastest-moving outcome.

Quality of life and biomarkers

“Significant” quality-of-life improvement rose from 5.4% at 1 month to 51.5% after more than 12 months.

The authors caution this shouldn't be read as proof that improvement automatically grows over time: the study was observational, and women who kept treatment going may have been more likely to be responders.

In a subset of 120 women with paired labs at baseline and 12 weeks: total and free testosterone increased, SHBG decreased, hemoglobin rose while staying within normal limits, and triglycerides fell 12.6%. The authors call these favorable changes — but the design can't prove causality.

What this means in real life

For women in perimenopause or menopause, the daily problem is practical: Can I think clearly today? When should I do deep work? Why did I crash after lunch? Should I move that meeting?

Joise is built around exactly that kind of day-to-day planning: it turns wearable sleep data and symptom logs into a daily focus forecast, helping you plan deep work, meetings and recovery without guessing.

Important caveats

This doesn't mean every woman with fatigue or brain fog needs testosterone, and it doesn't prove testosterone caused the improvements. It was a retrospective observational study, not a randomized controlled trial. Symptoms were self-reported at a single post-treatment point, with no baseline score, no control group, no adjustment for factors like BMI or menopausal status, and no systematic capture of adverse effects.

The grounded takeaway: if you're tracking menopause symptoms, don't track libido alone. Energy, mood, concentration, memory, sleep disruption and daily functioning may matter just as much — especially if your main struggle is staying sharp at work.

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Menopause brain fog at work?

Joise helps you stop guessing. Get a daily focus forecast built from your wearable sleep data and symptom patterns — so you can plan deep work, meetings and recovery around your real capacity.

Source: Elggren et al. Testosterone Replacement Therapy in Women Is Associated with Improved Symptom Burden and Favorable Biomarker Changes: A Retrospective Observational Study. Journal of Personalized Medicine, 2026.

Not medical advice. This article summarizes one observational study and should not be used to start, stop or change hormone therapy. Talk to a qualified clinician about your personal situation.