Here's what to know. Medically reviewed by Alyssa Dweck, MS, MD, FACOG Medically reviewed by Alyssa Dweck, MS, MD, FACOG The corpus luteum forms from the empty follicle left behind after ovulation.

Progesterone is produced by the empty follicle in the ovary after the egg has been released. This hormone maintains the lining of the uterus during the second half of the menstrual cycle.