Progesterone is a steroid hormone produced mainly by the ovaries in women and in smaller amounts by the adrenal glands and testes in men. In women, it prepares the uterine lining for implantation of a fertilized egg and maintains pregnancy by preventing uterine contractions. In men, it serves as a precursor for other hormones, including testosterone.
Normal Ranges
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Women
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Follicular phase: 0.06–0.89 ng/mL
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Ovulation (midcycle): 0.12–12.00 ng/mL
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Luteal phase: 1.83–23.90 ng/mL
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Postmenopausal: 0.05–< 0.13 ng/mL
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Men: 0.05–0.15 ng/mL
Clinical Uses
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Fertility assessment: Confirms that ovulation has occurred and evaluates corpus luteum function.
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Infertility workup: Helps identify luteal phase defects or anovulation.
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Pregnancy monitoring: In assisted reproduction, ensures adequate progesterone support for implantation.
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Ectopic pregnancy evaluation: Low levels may raise suspicion for nonviable or ectopic pregnancy.
Symptoms of Abnormal Levels
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Low progesterone
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Irregular or absent menstrual periods
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Difficulty conceiving
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Severe premenstrual syndrome (PMS)
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High progesterone
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Fatigue and drowsiness
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Weight gain and fluid retention
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Mood swings and irritability
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Testing
Progesterone is measured via a blood test, typically drawn during the luteal phase (about 7–10 days after ovulation). Results are interpreted alongside other hormone levels (e.g., LH, FSH, estradiol) and clinical findings.
Frequently Asked Questions
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Why is progesterone tested?
To confirm ovulation, assess luteal phase adequacy, and support pregnancy evaluation. -
When should the test be done?
Ideally during the mid-luteal phase of the menstrual cycle. -
Is fasting required?
No—progesterone testing does not require fasting. -
What do low levels mean?
Often indicate a luteal phase defect or inadequate corpus luteum function. -
What do high levels indicate?
May reflect progesterone supplementation or, rarely, hormone-secreting tumors.
