What are vasomotor symptoms?

Vasomotor symptoms (hot flashes and night sweats) are the most recognisable symptoms of menopause and perimenopause. A hot flash is a sudden sensation of warmth, often most intense in the face, neck, and chest, sometimes accompanied by sweating, flushing, and a rapid heartbeat. Night sweats are the same physiology happening during sleep, often disrupting sleep substantially. Most women experience at least some vasomotor symptoms during the menopause transition; for many, the symptoms are bothersome enough to seek treatment, and for some they continue for years.

Why they happen. The brain's thermoregulatory centre helps keep body temperature within a narrow range. Falling estrogen levels affect the thermoregulatory pathway and narrow the range that the brain accepts before triggering heat-loss responses (sweating, vasodilation). Even small temperature increases that would not normally trigger a response can now produce a hot flash.

The biology behind the new therapy. Within the thermoregulatory pathway, neurons that signal through neurokinin (NK) receptors play an important role in driving the inappropriate heat-loss response. Blocking these receptors quiets the inappropriate signalling and reduces hot flash frequency and severity.

The therapy options.

Menopausal hormone therapy: estrogen-based therapy (with a progestogen for women with a uterus) is the most-effective option for vasomotor symptoms and addresses other menopausal symptoms as well. Modern hormone therapy has multiple formulations and delivery routes; risk-benefit assessment is individualised.

Non-hormonal medicines: SSRIs and SNRIs at lower doses than for depression, gabapentin or pregabalin, and clonidine provide modest vasomotor symptom benefit. These are options for women who cannot or prefer not to use hormone therapy.

Mechanism-targeted non-hormonal therapy: fezolinetant blocks NK3 receptors in the thermoregulatory pathway and reduces vasomotor symptoms substantially. Elinzanetant blocks both NK1 and NK3 receptors and adds benefit for sleep disturbance associated with vasomotor symptoms. Follow-on NK-pathway medicines are in late-stage development.

The breast cancer survivor case. Women with a history of breast cancer, particularly hormone receptor-positive breast cancer, generally cannot use hormone therapy for vasomotor symptoms. Non-hormonal medicines and the new NK-pathway therapy are particularly meaningful for this population.

What to expect. Most women find a workable approach to vasomotor symptoms with the modern range of options. The conversation with a clinician centres on what is bothering you most, what your preferences are, and what your individual risk profile is. Vasomotor symptom therapy is no longer a hormone-or-nothing choice; the non-hormonal and mechanism-targeted options have meaningfully widened the practical pathway.