How long does GnRH analogue therapy take to work for endometriosis?

These medicines alter signals between the brain and ovaries, lowering the hormonal stimulation that can support endometriosis activity. Some people notice an early change in bleeding or pain, while others need follow-up before the benefit is clear. Symptoms can briefly change at the start, and menopausal-type effects such as hot flushes, vaginal dryness, mood changes, or sleep disruption may occur. The treatment is usually time-limited or carefully monitored because hormone suppression affects more than pelvic pain.

Take or attend treatment exactly as prescribed and keep a record of pain, bleeding, sleep, and side effects. Do not stop injections or tablets without discussing it with the prescribing clinician. Ask whether add-back hormones, a bone-health plan, or a review appointment is appropriate for you. If pain has not begun to change by the review point, the team can reassess the diagnosis, dose, duration, or another treatment option. More information about the condition is available in [Endometriosis](/conditions/endometriosis/), and treatment details are in [GnRH Analogue Therapy](/treatments/medical-gynaecology/gnrh-analogue-therapy/).

Tell your clinician about severe or worsening pelvic pain, heavy bleeding, troublesome mood changes, or symptoms that make daily activities difficult. Seek urgent help for sudden severe abdominal pain, fainting, heavy bleeding with weakness, chest pain, or difficulty breathing. Contact the prescribing team promptly if you may be pregnant, miss a scheduled dose, or develop a concerning reaction after treatment.

Ask which improvement should appear first, when your response will be reviewed, how long treatment is planned, whether add-back therapy is suitable, and how bone health or fertility planning affects the choice.