Why is GnRH agonist used in ovarian stimulation?

During ovarian stimulation, prescribed hormones encourage several follicles to grow. A GnRH agonist can first quiet the body's own cycle signals, allowing the fertility team to coordinate stimulation more closely. Depending on the protocol, it may also be used to help prevent an early hormone surge that could release eggs before the planned procedure.

The medicine is not the same as the hormone that directly grows follicles. Its role is to manage signalling and timing around the stimulation plan. The exact start date and dose depend on cycle pattern, scan findings, blood tests, and the other medicines being used. More detail is available in [GnRH Agonist](/materials/gnrh-agonist/).

Take each dose at the prescribed time and keep scan or blood-test appointments, because these checks show how follicles and hormone levels are responding. You may notice hot flushes, headache, mood changes, or local irritation. Tell the clinic about symptoms and about every medicine or supplement you use.

If a dose is late or missed, contact the fertility team for instructions rather than taking an extra dose on your own. Keep medicines stored as directed and bring questions to the next monitoring visit.

Call the fertility clinic promptly if you develop increasing abdominal swelling, worsening pelvic pain, vomiting, or rapid weight change during stimulation. Seek urgent care for severe pain, breathing difficulty, faintness, or very little urine. These can signal a significant treatment reaction and should be assessed quickly.

Ask why this protocol was selected, when the agonist should begin and end, and which scan or blood-test findings guide adjustments. Ask what to do after a missed dose, which symptoms are expected, and who to contact outside clinic hours.