Written by: Dr. Amy Beckley, PhD, Founder and Inventor of the Proov test — the first and only FDA-cleared test to confirm successful ovulation at home.
Written on 1/18/21
Progesterone is one of the most important female reproductive hormones, also known as the pregnancy hormone. It plays a vital role when you are trying to conceive and once you get pregnant by nourishing the uterine lining the embryo attaches to.
But even if you aren’t trying to have a baby, progesterone could be a good indicator of your overall health. An optimal level post-ovulation ensures a healthy luteal phase and balances the effects of estrogen. Progesterone is also related to breast, cardiovascular, and nervous system health.
However, there are quite a few misconceptions surrounding progesterone. It is very important to separate myth from facts, so that you know where you stand and how to act in the event that your progesterone levels are off.
It is very important to separate myths from facts, so that you know where you stand and how to act in the event that your progesterone levels are off.
Myth #1: If you ovulate, your progesterone levels are fine.
Sadly, wrong! Ovulation doesn’t guarantee adequate progesterone levels.
After an egg is released, the corpus luteum forms in the place of the empty follicle and starts producing progesterone. If your progesterone levels rise and remain elevated throughout your luteal phase, you should expect your next period to arrive 12-14 days post-ovulation. Unfortunately this isn’t always the case.
If the ovulation isn’t “strong” enough, your progesterone levels may be suboptimal which can lead to a luteal phase defect. This means that an egg was released but progesterone didn’t remain elevated for long enough to allow for the best possible chance at conception. You may suspect you have this problem if you spot before your period, your luteal phase is shorter than 12 days, or you have difficulty getting pregnant.
If you do conceive, your levels should stay elevated as the corpus luteum produces enough progesterone to nourish the pregnancy until the placenta takes over by the end of the first trimester. Low progesterone in early pregnancy may cause miscarriage.
Most doctors and labs will confirm ovulation in blood at levels above 5 ng/ml doctors typically like to see progesterone at 10 ng/ml minimum in order to support successful conception.
Myth #2: If progesterone levels are adequate on cycle day 21, your levels are fine.
This is probably the most common myth regarding progesterone. It can be true if your cycle is consistently 28 days long because progesterone levels are known to peak 7 days post ovulation.
For most women though, 7 days after ovulation doesn’t always coincide with cycle day 21 because their cycles are not exactly 28 days long. This accounts for many women, as cycle lengths can vary anywhere from 22 to 36 days.
Does progesterone fluctuate during the day? Yes, progesterone levels can fluctuate day to day, even hour to hour. As we previously mentioned, progesterone needs to rise and remain elevated for several days to allow for a healthy luteal phase length. A cycle day 21 progesterone blood test only shows levels at one point in time. This could provide an inaccurate assumption about your levels since progesterone fluctuations throughout the day can fluctuate up to 8 times in a single 90-minute period.
To get an accurate understanding of your fluctuating progesterone levels and luteal phase health, ideally you should test progesterone several days in a row and take the average of these measurements.
To get an accurate understanding of your progesterone levels and luteal phase health, ideally you should test progesterone several days in a row and take the average of these measurements.
Myth #3: You must have 3 consecutive miscarriages to be prescribed progesterone.
In an ideal world, we believe no woman should have to suffer a miscarriage in order to be prescribed progesterone. When trying to conceive, it is essential to track your LH surge in order to time intercourse more accurately. Once ovulation has occurred, you should have your progesterone levels tested, to make sure they are high enough to sustain a pregnancy, in case implantation takes place.
Unfortunately, there are medical systems that do not recommend testing unless a couple has already had three early miscarriages. This is where getting educated and advocating for yourself really makes a difference! If you’d like to speak to a doctor about progesterone concerns, you can schedule a consultation here.
Low progesterone is the most common preventable cause for early miscarriage and it is typically easy to address. Having it diagnosed early may save you a lot of money, time and heartache.
Myth #4: A progesterone blood test is the best way to confirm ovulation.
As we’ve seen, progesterone blood tests can provide flawed results. While a blood test can confirm that you did or did not ovulate, they cannot confirm that ovulation was “successful.” Successful ovulation refers to an ovulatory event in which an egg is released and progesterone levels remain adequately elevated for a long enough period of time.
Blood tests only provide progesterone levels at one point in time and these levels can fluctuate drastically during a 24-hour window. Because of this, having your blood drawn at a few hours distance may indeed give you two very different values.
The solution to this, as we mentioned, is to test progesterone levels in blood for 3 or 4 days in a row and take an average of these levels in order to confirm successful ovulation. However, this can be inconvenient because it is invasive, expensive, and requires daily access to a lab.
Blood tests only provide progesterone levels at one point in time and these levels can fluctuate drastically during a 24-hour window.
Why PdG tests are better for confirming successful ovulation
Once it circulates through your blood, progesterone is being metabolized by your kidneys and excreted in urine as PdG. Scientists have been studying PdG for over 60 years and concluded PdG levels in urine correlate with progesterone serum levels. They also noticed that PdG levels in morning urine are not subject to the progesterone fluctuations in blood.
Proov is the first and only FDA cleared PdG test kit to confirm successful ovulation at home. Since Proov measures PdG levels in urine, Proov tests are non-invasive and make it easy to measure PdG levels several days in a row. Testing with Proov on days 7, 8, 9, and 10 after peak fertility confirm that successful ovulation did in fact occur.
Progesterone is an important hormone for your fertility and general health. Knowing the facts (and myths) about progesterone can help you live your best life and reach your fertility goals faster.