In women, normal progesterone levels from the first to the 14th day of the menstrual cycle are less than 1 nanogram per milliliter, according to WebMD. From the 15 until the 28th day of the menstrual cycle, normal progesterone levels are around 2 to 25 nanograms per milliliter. In men, normal values are less than 1 nanogram per milliliter.
WebMD states that the amount of progesterone in the blood is measured through the progesterone test. Normal values, also called reference ranges, vary from one laboratory to another. A patient can find out the reference range that a particular laboratory uses by looking at her lab report. Doctors examine the results based on the patient's health and other factors, meaning that normal values can be different from person to person. Any substantial abnormal results are usually discussed by the doctor.
There are numerous conditions that affect progesterone levels, says WebMD. High progesterone values are likely caused by pregnancy, overproduction of hormones by the adrenal glands, or a cancer of the ovaries or adrenal glands. Problems with ovulation and possible miscarriage can result in low progesterone values. Normal progesterone levels during the first trimester of pregnancy are 10 to 44 nanogram per milliliter, while progesterone levels after menopause are normally less than 1.0 nanogram per milliliter.