what is progesterone

Progesterone is an endogenous steroid and progestogen sex hormone that plays a crucial role in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called progestogens and is the major progestogen in the body. Progesterone is involved in preparing the endometrium for a fertilized egg to implant and grow, and if pregnancy occurs, it supports the pregnancy by stimulating the growth of blood vessels that supply the lining of the womb and helps maintain the endometrium throughout pregnancy. It is also used as a medication, such as in combination with estrogen for contraception, to reduce the risk of uterine or cervical cancer, in hormone replacement therapy, and in feminizing hormone therapy