Progesterone blood test: what it checks and how to prepare
A progesterone test measures progesterone in a sample of your blood. Progesterone is a hormone made mainly by the ovaries. Most women look into the test for one of two reasons: to see whether they ovulated, or to follow up on irregular periods or trouble getting pregnant.
Progesterone
The lowest-priced test here for progesterone.
$45
See this test at HealthLabsPrice checked October 2026. Not available in ND, RI, NY, NJ, MD and HI. We earn a commission on sales.
What the test measures
According to MedlinePlus, progesterone prepares the lining of the uterus for pregnancy. In the first half of a typical cycle, estrogen thickens that lining. In the second half, after an ovary releases an egg, progesterone starts to rise. If you do not become pregnant, progesterone falls and your period begins.
That rise and fall is why one result can look very different from another, even in the same person.
Why it is ordered
MedlinePlus lists these reasons for a progesterone test:
- To see whether your ovaries are releasing eggs (ovulating) normally when you have trouble getting pregnant.
- To check whether fertility treatments are working.
- To look into abnormal uterine bleeding when you are not pregnant.
- To help find an ovarian or adrenal gland problem.
- To check on a pregnancy that has a higher risk of complications.
Pregnancy is outside what this site covers. If you are pregnant or think you might be, talk to a clinician rather than relying on a lab order from a website.
How to prepare
MedlinePlus says you usually don’t need any special preparation. In some cases you may need to know the first day of your last menstrual period, so have that date handy. Your provider will tell you if you need to stop a medicine before the test. Don’t stop a medicine unless your provider says to.
The seller’s page for this test describes a simple blood draw, says fasting is not required, and says results appear in your online account within one to three business days. If your lab order says something different, follow the lab order. More in fasting before a blood test.
Timing
The seller’s page notes that progesterone changes through the cycle and that timing is important. It does not give an instruction for which day to book. Follow the lab order, or ask the clinician who ordered it. If your cycles are not 28 days, “day 21” may not match your cycle. The cycle timing tool shows how your own cycle length shifts the picture.
Blood test or home kit
This page is about the blood test. For the difference between kits you use at home and a test taken at a lab, see at-home tests vs lab tests.
Reading your result
A single progesterone number does not diagnose anything on its own. Its meaning depends on why you were tested, where you were in your cycle, and whether you were pregnant. Reference ranges also differ from lab to lab, so compare your result with the range printed on your own report. See progesterone levels by cycle phase for one published set of ranges, and low progesterone for what a low result can mean.
See a clinician if your periods are missing or irregular, if you have been trying to get pregnant for a year without success, or if a result is outside the range on your report.
Progesterone
$45
See this test at HealthLabsPrice checked October 2026. Not available in ND, RI, NY, NJ, MD and HI. We earn a commission on sales.
Keep reading
- Progesterone levels by cycle phase and after menopause
Published progesterone reference limits for the follicular phase, the luteal phase and after menopause, with units, plus why your lab's range may differ.
- When to test progesterone: why "day 21" assumes a 28-day cycle
The day 21 progesterone test assumes a 28-day cycle with ovulation on day 14. See why that fails for many cycles, and why to follow the day on your lab order.
- Low progesterone: what a low result can mean
A low progesterone result is normal at some points in life and a signal at others. See what it can mean, why timing matters, and when to see a clinician.