How long does hormone therapy for breast cancer take to work?

These medicines reduce hormone stimulation or block the way cancer cells respond to hormones. The treatment may be used before or after other treatment, or for breast cancer that has returned or spread. The first sign of benefit depends on the treatment goal: a scan, examination, blood test, or change in symptoms may provide useful information. A lack of an immediate change does not by itself show that treatment has failed.

Your oncology team chooses the review point according to the medicine, the extent of disease, previous treatment, and your general health. Some side effects can begin before any visible response; they are not a reliable measure of whether the cancer is responding.

Take the medicine on the schedule prescribed and tell your team about missed doses, new medicines, or supplements. Keep appointments for examinations and planned imaging, because these checks show whether the treatment is meeting its purpose. Do not stop treatment because improvement is not yet noticeable; ask how your team will measure response and when that review is planned.

Record symptoms such as pain, breathlessness, swelling, hot flushes, or changes in mood. A simple treatment diary can help separate expected effects from symptoms that need attention. More information about this treatment is available in [Hormone Therapy for Cancer](/treatments/systemic-therapy/hormone-therapy-for-cancer/).

Contact your oncology team promptly if symptoms are getting worse, a new lump or swelling appears, pain is not controlled, or you cannot keep your medicine down. Seek urgent help for severe breathlessness, chest pain, sudden weakness, confusion, or heavy bleeding. These symptoms need assessment regardless of how long treatment has been underway.

Ask which result will show that the treatment is helping, when that result will be checked, and what the next step would be if the response is smaller than expected. You can also ask whether the medicine is intended to control cancer, reduce the chance of recurrence, or prepare for another treatment.