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 3/9/21
Low progesterone is a hormone imbalance that can lead to unpleasant symptoms and make it harder to get pregnant.
Understanding our hormone levels is so important when trying to conceive, but also for our overall health. Low progesterone is a hormone imbalance that can lead to unpleasant symptoms and make it harder to get pregnant.
Keep reading to learn how common low progesterone is and what you can do about it.
What is low progesterone?
Progesterone is a hormone released after ovulation by the empty follicle (a.k.a. corpus luteum). Its main function is to stabilize the uterine lining and make it “sticky” enough to allow implantation to occur, in the case that the released egg is fertilized. Progesterone is also called the “pregnancy hormone” as it creates a healthy uterine environment in which an embryo can thrive.
During the first half of your cycle, progesterone levels should be low and remain low until ovulation occurs. Then, levels should start rising immediately after ovulation. Progesterone should reach an optimal level about 7 days after ovulation and should remain high throughout your luteal phase.
If you successfully conceive, progesterone remains elevated and the placenta takes over production in order to help the uterus grow and prevent premature contractions. If you do not conceive that cycle, progesterone levels drop at the end of the luteal phase. Your uterine lining starts shedding and your period arrives.
Low progesterone is a hormonal imbalance that occurs when one of two things happen. Either ovulation doesn’t occur so there’s no empty follicle to produce progesterone or ovulation does occur, but the corpus luteum doesn’t produce enough progesterone for long enough to maintain a healthy luteal phase.
Low progesterone can mean that your uterine lining isn’t well-prepared for implantation and your luteal phase may be shorter, both of which can lead to infertility or recurrent miscarriages.
How common is low progesterone?
In short, low progesterone is all too common among women. And, more often than not, low progesterone is misdiagnosed.
Even though it has been researched for over 60 years, there is still a lack of consensus in the scientific community regarding the luteal phase defect caused by low progesterone. One of the main causes of this would be that luteal phase defect used to be difficult to diagnose, due to the unreliability of progesterone blood testing during the luteal phase — more on this later!
Even though it has been researched for over 60 years, there is still a lack of consensus in the scientific community regarding the luteal phase defect caused by low progesterone.
Nevertheless, a recent study states, “[luteal phase defect] has been diagnosed in 3-20% of patients who are infertile and in 5-60% of patients experiencing recurrent pregnancy loss.” However, the same study also calls for more research since an inadequate luteal phase has also been found in anywhere from 6-10% of fertile women.
Moreover, two other recent studies concluded that progesterone could prevent 8,500 miscarriages per year in women with a history of recurrent miscarriage or early pregnancy bleeding. The increase in the live birth rate went from 3% to 15%, with progesterone being a cost-effective and easy-to-administer solution.
What causes low progesterone?
Low progesterone may be caused by various factors, including:
Polycystic ovarian syndrome (PCOS): PCOS is one of the most common causes of ovulatory dysfunction and low progesterone. Women with PCOS have excess androgens (male sex hormones) that can lead to hormone imbalances that inhibit ovulation. Without ovulation, there is no corpus luteum to produce progesterone.
Stress: Stress increases your cortisol — the stress hormone — levels. Since progesterone and cortisol are produced on the same hormone pathway, your body may “steal” progesterone in order to produce more cortisol when your body is under a lot of stress.
Excess exercise: Similarly to stress, excess exercise (like Crossfit or marathon training) can cause your body to produce excess cortisol, and then lead to low progesterone. Note that moderate, less-intense exercise is not harmful to progesterone levels.
Hypothyroidism: Progesterone and your thyroid have a reciprocal relationship. Estrogen dominance (caused either by high estrogen or by low progesterone) can cause a deficiency in thyroid hormone levels. On the flip side, without enough T3 and T4 (thyroid hormones) your body may struggle to produce enough progesterone.
Abnormal body weight: Being underweight can be a cause of anovulation, which results in low progesterone levels. On the other hand, excess fat cells produce excess estrogen which disrupts the estrogen-progesterone balance.
Low progesterone may be caused by various factors, including PCOS, stress, abnormal bodyweight, excess exercise, or hypothyroidism.
How do I tell if I have low progesterone?
Tracking your cycle and hormone levels is essential to understanding if low progesterone is a concern. If your cycles are irregular, you may not ovulate at all. If your luteal phase is short or you spot a few days before your period arrives, these may be low progesterone symptoms — even if you’re ovulating.
However, simply assuming you have low progesterone isn’t good enough; measuring your progesterone levels during the luteal phase is a good way how to test progesterone and it will give you a better idea of if levels are lower than they should be.
Yet studies have shown that progesterone is released into the bloodstream in sporadic pulses, meaning fluctuations are drastic — we’re talking up to 8 times in a single 90-minute period in the same healthy subject! Since serum progesterone tests only show levels at a single point in time, a blood measurement could give you an inaccurate assumption about your levels.
And, as we’ve seen, progesterone levels need to rise and remain elevated throughout the luteal phase in order to be considered healthy. This is also referred to as a healthy ovulatory event. Testing progesterone levels over time would require multiple blood draws on consecutive days — ouch!
Luckily, there’s a non-invasive, convenient way to measure progesterone levels: PdG testing!
PdG is a urine metabolite of progesterone. After circulating through your blood, progesterone gets excreted in urine where it can be measured in the form of PdG.
Not only do PdG and progesterone levels correlate, but PdG levels are not subject to the same fluctuations as serum progesterone. Testing PdG levels in first morning urine reflects the average of what your progesterone levels in blood were the day before.
Proov PdG tests are the first and only FDA cleared PdG tests to confirm successful ovulation at home. Testing PdG levels on days 7, 8, 9, and 10 after peak fertility confirms that successful ovulation did in fact occur, meaning PdG levels remained elevated for long enough to allow for the best possible chance at conception.
Proov PdG tests are the first and only FDA cleared PdG tests to confirm successful ovulation at home.
We like to see 3-4 positive Proov tests during the testing window to confirm successful ovulation. If you get anything less than 3 positive tests, this could be a sign of “weak” ovulation or low PdG levels.
Ideally, all 4 of your Proov tests should be positive to confirm successful ovulation. However, if your first Proov test is negative, but the remaining 3 are positive, we still consider your ovulation to be successful.
If on the other hand, your first 3 are positive and your last test is negative, this means your PdG levels are dropping too soon and could be a sign of weak ovulation. Weak ovulation refers to lower-than-ideal PdG (and therefore progesterone) levels after ovulation.
If you get anything less than 3 positive Proov tests, this could be a sign of weak ovulation and we recommend consulting your doctor.
How do I treat low progesterone?
Sometimes, a few simple lifestyle and dietary changes may help improve progesterone levels.
Diet may negatively or positively impact your ovulation. A poor diet may cause your hormones to get out of whack, which in turn may affect the health of your ovulation and progesterone levels. Reducing sugar, processed foods and trans fats, and eating a healthy diet with more fiber, foods rich in antioxidants, whole grains, and leafy greens may boost progesterone levels.
Exercise of moderate intensity is a good way to alleviate stress and maintain a healthy body weight. Studies show that women who eat balanced meals and engage in 30 minutes of physical activity daily had much lower risk of infertility due to ovulatory disorders (such as low progesterone).
Herbal supplements, when taken under the supervision of a certified herbalist or doctor, may be a good way to balance your hormones and promote healthy ovulation. Herbals like vitex, maca, and ashwagandha are great options for improving progesterone levels.
If you’ve tried natural methods and are still experiencing low progesterone, you may need prescription-strength progesterone supplementation under the form of suppositories or pessaries. If you’re interested in stronger support, we recommend consulting your doctor.
Knowing the role progesterone plays in conception and your overall health allows you to take the necessary measures to make sure your levels are optimal, while giving you the necessary tools to improve your ovulation.
While low progesterone is common, there are plenty of ways to measure and treat it! Understanding your progesterone levels is key to getting pregnant faster.