Progesterone

About This Test
Progesterone is the hormone made after ovulation that prepares the uterine lining and supports early pregnancy. Levels rise in the luteal phase and are lower if ovulation did not occur. Doctors interpret progesterone together with LH, FSH, estradiol, and ultrasound to understand fertility and cycle health. This test is commonly used in fertility work-ups and cycle tracking.

Patient Preparation
No fasting needed. For fertility testing, sample 7 days before your expected period (e.g., around day 21 of a 28-day cycle) or as your doctor advises.

Best Time to Test
Morning preferred, but can also be done anytime

Tests Included
Progesterone

Why is it done
Confirming ovulation and timing fertile windows; evaluation of irregular cycles, infertility, or early pregnancy concerns; assessing luteal phase adequacy; monitoring progesterone therapy in fertility or pregnancy care; clarifying suspected anovulation (e.g., PCOS).