Progesterone is a female hormone, produced primarily in the ovary, primarily
during the second half ("luteal phase") of the menstrual cycle.
Men also produce progesterone, but only very small amounts.
Shortly after ovulation, progesterone levels rise quickly and remain
elevated for about 10 days.
- If pregnancy occurs, the progesterone levels remain elevated.
- If pregnancy does not occur, then progesterone levels fall, provoking
a menstrual flow.
Progesterone levels are sometimes used to evaluate a possible ectopic
- If progesterone > 25, ectopic pregnancy is very unlikely
- When less than 25, the results are not conclusive either way.
Elevations found in:
- Second half of the menstrual cycle
- Congenital adrenal hyperplasia
- Some hormone-producing tumors of the ovary
Decreases found in:
- Polycystic Ovary Syndrome (PCO, Stein-Levinthal Syndrome)
- Amenorrhea-Galactorrhea Syndrome
- Luteal phase defects
- Ovarian failure
||< 1.0 ng/ml
|< 1.5 ng/ml
*These are general values taken from a variety of
sources. The actual normal values may vary from lab to lab and from one
type of testing protocol to another.