From the Research
Normal progesterone levels vary depending on a person's sex, age, and reproductive stage, with levels typically low at less than 1 ng/mL during the follicular phase, rising to 5-20 ng/mL during the luteal phase, and increasing dramatically during pregnancy. In women of reproductive age, progesterone levels fluctuate throughout the menstrual cycle, as noted in a study on physiological changes associated with the menstrual cycle 1. During the follicular phase, levels are typically low, while after ovulation, during the luteal phase, progesterone rises significantly.
Key Points to Consider
- During pregnancy, progesterone levels increase dramatically, reaching 10-50 ng/mL in the first trimester and potentially exceeding 200 ng/mL by the third trimester, as discussed in a study on progesterone and pregnancy 2.
- In postmenopausal women, progesterone levels remain consistently low at less than 1 ng/mL.
- For men, normal progesterone levels are typically less than 1 ng/mL throughout life.
Clinical Implications
These variations reflect progesterone's crucial roles in the female reproductive system, including preparing the uterus for potential pregnancy, supporting early pregnancy, and regulating the menstrual cycle, as highlighted in a study on progesterone in normal and pathological pregnancy 3. Abnormal progesterone levels may indicate various conditions such as anovulation, luteal phase defects, pregnancy complications, or certain types of tumors, which is why progesterone testing is often used in fertility assessments and pregnancy monitoring.