Progesterone
What it measures, and what changes the number.
Progesterone is a steroid hormone produced mainly by the ovaries after ovulation, by the placenta in pregnancy, and in smaller amounts by the adrenal glands and testes. The test measures its concentration in blood, reported in nmol/L or ng/mL depending on the lab.
It is often read with estradiol, LH and FSH to follow the menstrual cycle, and with beta-hCG in early pregnancy. 17-OH progesterone, a related but different hormone, is sometimes ordered at the same time and should not be confused with it.
Timing is the main factor: levels change greatly across the menstrual cycle, so the cycle day of the draw matters when comparing results. Hormone preparations containing progesterone or similar compounds can also affect immunoassays. Different assays give somewhat different values, and unit conversions between nmol/L and ng/mL need care. Labs may print it as Progesterona.
Reference ranges labs publish
Each lab states an interval for its own method and the population it measured. They differ, they are not interchangeable, and none of them is a verdict on a single result.
- Men, 18 years and over: up to 0.2 ng/mL (no lower limit stated) (up to 0.636 nmol/L) · ECLIA (immunoassay) · Source: Mayo Clinic Laboratories, PGSN (Progesterone, Serum) (read 2026-09-24)
- Men, all ages: 0 to 0.5 ng/mL (0 to 1.59 nmol/L) · ECLIA (immunoassay) · Source: Labcorp, 004317 (Progesterone) (read 2026-09-24)
- Women, 18 years and over, follicular phase: up to 0.89 ng/mL (no lower limit stated) (up to 2.83 nmol/L) · ECLIA (immunoassay) · Source: Mayo Clinic Laboratories, PGSN (Progesterone, Serum) (read 2026-09-24)
- Women, 18 years and over, midcycle (ovulation): up to 12 ng/mL (no lower limit stated) (up to 38.2 nmol/L) · ECLIA (immunoassay) · Source: Mayo Clinic Laboratories, PGSN (Progesterone, Serum) (read 2026-09-24)
- Women, 18 years and over, luteal phase: 1.8 to 24 ng/mL (5.72 to 76.3 nmol/L) · ECLIA (immunoassay) · Source: Mayo Clinic Laboratories, PGSN (Progesterone, Serum) (read 2026-09-24)
- Women, 18 years and over, postmenopausal: up to 0.2 ng/mL (no lower limit stated) (up to 0.636 nmol/L) · ECLIA (immunoassay) · Source: Mayo Clinic Laboratories, PGSN (Progesterone, Serum) (read 2026-09-24)
- Women, follicular phase: 0.1 to 0.9 ng/mL (0.318 to 2.86 nmol/L) · ECLIA (immunoassay) · Source: Labcorp, 004317 (Progesterone) (read 2026-09-24)
- Women, midcycle (ovulation): 0.1 to 12 ng/mL (0.318 to 38.2 nmol/L) · ECLIA (immunoassay) · Source: Labcorp, 004317 (Progesterone) (read 2026-09-24)
- Women, luteal phase: 1.8 to 23.9 ng/mL (5.72 to 76 nmol/L) · ECLIA (immunoassay) · Source: Labcorp, 004317 (Progesterone) (read 2026-09-24)
- Women, postmenopausal: 0 to 0.1 ng/mL (0 to 0.318 nmol/L) · ECLIA (immunoassay) · Source: Labcorp, 004317 (Progesterone) (read 2026-09-24)
Usually reported in nmol/L or ng/mL.
Often read alongside: Estradiol (E2), LH, FSH, Beta-hCG, 17-OH progesterone