Progesterone too high or too low: how to read the reference ranges

This test measures the amount of progesterone in your blood, in nanomoles per litre (nmol/l). Your body produces this hormone mainly after an ovulation, which is why the table on this page reads by cycle phase.

Before ovulation, in the follicular phase, the result belongs below 0.62 nmol/l. Around ovulation 0.18 to 13.2 nmol/l is usual. After ovulation, in the luteal phase, the value rises to 13.1 to 46.3 nmol/l. For men the ceiling sits at 0.47 nmol/l, and after menopause at 0.4 nmol/l. No lower bound applies to those groups, because the measurement does not reach that low: anything below 0.159 nmol/l is reported by the lab as less than that limit, and that is simply normal. These values do not apply during a pregnancy, because progesterone then runs far higher than the luteal range. They belong to the Roche Elecsys method; another lab with another method prints other numbers.

The right moment to draw falls seven days before the next period. The second half of the cycle lasts about fourteen days in almost everyone; the first half varies. In a 28-day cycle that is day 21, in a longer cycle the moment shifts later. Draw on day 21 in a 35-day cycle and you are still before ovulation, so a low result is no abnormality.

Progesterone is released in pulses, so a result close to a limit is better repeated in a following cycle. Hormonal contraception blocks ovulation and thereby keeps the result low; that is the method at work and says nothing about your body.

This is the blood value that shows, after the fact, whether you ovulated. A urine ovulation test measures the hormone that announces ovulation; progesterone measures what happens afterwards. The luteal reference values were established in women who demonstrably ovulated, so 13.1 nmol/l is in effect the lower limit of a cycle with ovulation.

That is why the most important result from this test is a low value on the right day. It says there was no ovulation in this cycle, or that the day was wrong. The second happens often: anyone drawing on a fixed day 21 in a 32- or 35-day cycle is still measuring the first half and gets a low value that means nothing. So always note when your period came afterwards; that tells you whether the timing was right.

If you are trying to conceive, this is the number your doctor starts with if your cycle is irregular. Long or unpredictable cycles without ovulation are the most common hormonal reason conceiving does not work. If you have a regular cycle of normal length, the Dutch GP standard actually advises against this test: a regular cycle already points strongly to ovulation on its own, and the test then adds little.

What you do not get from it: a precise threshold above which ovulation is proven. The figures circulating for that, such as 16 or 30 nmol/l, appear in no current guideline and therefore not on this page. Nor can complaints such as fatigue or mood swings be read from one progesterone value. If you want the whole picture of your cycle, your FSH and LH at the start of the cycle come into it, and your TSH and prolactin if ovulation is failing to occur.

Draw seven days before the day you expect your period. In a 28-day cycle that is day 21, at 30 days day 23, at 35 days day 28. So count back from the end of your cycle, because the second half is the same length in almost everyone and the first half is not.

After the draw, write down when your period actually came. If it came more than ten days later, you were still in the first half of the cycle and a low value says nothing about your ovulation. If it came within five days, you drew at the end of the phase, when the value is already dropping. In both cases you draw again in a following cycle on a better chosen day.

With an irregular cycle the moment is hard to guess. A urine ovulation test helps: test six to eight days after it turns positive. You do not need to fast and the time of day makes little difference.

If you use the pill or other contraception that blocks ovulation, this test is not informative, because the value then stays low. If you take or use progesterone as a medicine, for instance during IVF treatment or as part of hormone therapy, say so, because the test measures it too. And if you could be pregnant, you are no longer measuring a cycle phase; have that result assessed by your midwife or doctor.