Progesterone vs. 17-hydroxyprogesterone

February 7, 2023 Response by  


Dear Doctor,
Is there a difference in labs testing for progesterone vs. 17-hydroxyprogesterone? Can you explain why would test for one, as opposed to the other, if there is? Thank you!


Progesterone (P) and 17-hydroxyprogesterone (17-OHP) are different hormones. 17-OHP is an intermediate derived from P on the pathway to forming cortisol, testosterone and estrogen.


Progesterone produced by the ovarian follicle after ovulation (the corpus luteum) that organizes and vascularizes the lining of the uterus. It is also produced by the placenta during pregnancy. It is measured during the menstrual cycle or pregnancy to check for ovulation or to see if there are healthy levels.

17-hydroxyprogesterone is tested to see if a rare condition, congenital adrenal hyperplasia (CAH). is present. Some forms of CAH have similar symptoms to the very common polycystic ovarian syndrome (PCOS), such as infrequent periods and excess hair growth. Measuring 17-OHP helps distinguish between these two conditions.


Both P and 17-OHP are manufactured in the injectable form to prevent pregnancy loss or preterm labor. Progesterone is also prepared in oral, vaginal or transdermal forms to prevent miscarriage and treat gynecologic conditions such as abnormal bleeding, premenstrual syndrome or menopausal therapy.

Mary Davenport, MD, MS