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Synthetic or plant versions of progesterone may be prescribed under a variety of conditions. They are also occasionally used as a diagnostic aid to measure the effect of estrogen on women who have stopped menstruating but who aren't in menopause yet.

In what is called a "progestin challenge" test, a woman takes progestin pills for five or more days. When she stops taking the progestin, bleeding should begin if estrogen is present (the source of the bleeding is the estrogen-thickened endometrial tissue). If bleeding does not occur, then she isn't making enough estrogen.

Sometimes the progestin challenge test is used to make sure a woman has reached menopause. If estrogen status remains unclear, a blood test for levels of another female hormone, follicle-stimulating hormone (FSH), may be ordered.

A progestin challenge test may also be done to identify postmenopausal women at high risk for endometrial cancer because they don't produce enough progesterone, particularly during postmenopausal hormone therapy. If the hormone therapy progestin dose is too low to make up for the estrogen part of the hormone therapy, the endometrium gradually builds up, a possible risk for uterine cancer.