What hormones change before a woman has her period?
Estrogen and Progesterone are the hormones that change; Estrogen builds up the lining of the uterus. Progesterone increases after an ovary releases an egg at the middle of the cycle. This helps the estrogen keep the lining thick and ready for a fertilized egg. A drop in progesterone causes the lining to break down. This is when your period starts. ChaCha!
