Hormones
The hypothalamus releases GnRH in pulses, the pituitary responds with FSH and LH, and the ovaries respond with oestradiol and progesterone that feed back to the brain. Disruption anywhere along the axis — from weight loss, excessive exercise, illness or medication — can stop ovulation.
Also known as: HPO axis, hormone axis
Related Canada guides
Sources
- Society of Obstetricians and Gynaecologists of Canada (SOGC) patient information
Last reviewed: September 9, 2026. Written by the Antega Editorial Team. General information only — always follow the advice of your own clinic, doctor or pharmacist.