Progesterone Deficiency: 3 Reasons Why Your Progesterone Level is Low

Maybe you had a blood test and your progesterone level came back lower than the specified normal range.

Or perhaps you’ve been struggling with PMS, irregular periods or infertility, and suspect that it may have something to do with your progesterone.

In either case, it’s important to know the symptoms and causes of progesterone deficiency, so that you can take steps to correct it.

Do you have progesterone deficiency

First, how do you know if your progesterone level is low?

The sure way to know is to get a blood test. And the best time to test your progesterone is 6-8 days after ovulation, when it peaks.

If you’re not sure about when you ovulate, around one week before your period is a good estimate.

Standard Reference Range for Progesterone

Here’s the standard reference range for progesterone:

• 0.2 – 0.8 ng/ml during follicular phase (the first half of your menstrual cycle)
• 4.1 – 23.7 ng/ml during luteal phase (the second half of your menstrual cycle)
• 0.1 – 0.6 ng/ml for post-menopausal

So if your progesterone level during the luteal phase is lower than 4.1 ng/ml, it indicates an insufficient level of progesterone.

However, it’s important to note that even if your progesterone level falls within the normal range, you can still experience signs of progesterone deficiency.

This may be due to high estrogen levels (estrogen dominance), or compromised progesterone functions (progesterone resistance), which we’ll discuss in more detail below.

3 Primary Causes of Progesterone Deficiency

Next, let’s see what can cause progesterone deficiency.

If your serum progesterone level is low or you experience signs and symptoms of progesterone deficiency, it’s important to understand the underlying causes.

Below are the three most common reasons why your progesterone level is low:

1. Little or No Ovulation

After ovulation, the dominant follicle is transformed into a corpus luteum, which releases progesterone to supply nutrients to the uterus for a potential implantation.

If ovulation does not occur, the progesterone level will remain low – and you’ll not see a rise of basal body temperature (BBT) during the second half of your menstrual cycle.

As you can see, ovulation is the key to the regular, monthly production of progesterone during the fertile years. And charting your ovulation can provide a visual clue to the hormonal changes in the body, even though they are invisible to the naked eye.

The good news is that once you get yourself acquainted with the three types of ovulation charts, it’s pretty easy to tell if you ovulate or not in any given cycle – allowing you to then gauge your progesterone level without taking a blood test.

2. Adrenal Fatigue

Although progesterone is mostly made in the ovaries, a small amount is produced in the adrenal glands, where it can be converted to other hormones, such as cortisol – the main stress hormone.

Stress is an inevitable part of life. The right amount of stress can make us stronger and is helpful for our growth.

However, too much stress for a prolonged period of time can wrack our natural hormone balance and harm our health and wellbeing.

This happens when there’s a high demand for cortisol and the body is unable to keep up with the supply. So it takes from cortisol’s prehormone, pregnenolone (the mother hormone of all sex hormones).

When more of pregnenolone is used to make cortisol, less will be available to make progesterone and estrogen. 

This may sound a bit technical but is quite easy to understand.

When you’re trying to run away from a tiger (in a fight or flight mode), making a baby (rest, digest and mate) would be the last thing on your mind.

So a healthy adrenal function is the foundation for estrogen and progesterone balance.

For this reason, it’s important to spot the signs of adrenal fatigue and learn natural ways to restoring your body’s adrenal balance.

3. Estrogen Dominance

One of the most important roles of progesterone is to counter balance estrogen.

When estrogen levels are too high, progesterone level will become relatively low. And there may be signs of estrogen dominance, as well as symptoms of progesterone deficiency, even though the serum level is normal.

Since estrogen dominance is such a common pattern of hormonal imbalance among women, I’ve discussed extensively on this important topic. Check out the following resources:

Signs and Symptoms of Estrogen Dominance

What Causes Excess Estrogen: 5 Leading Causes of Estrogen Dominance

How to Lower Estrogen Dominance

Additional Causes of Progesterone Deficiency

In addition to lack of ovulation, adrenal fatigue, and estrogen dominance, there are four other less common causes of progesterone deficiency that are worth considering:

4. Aging Ovaries

When we get older, our ovaries make fewer ripe eggs and ovulation may not take place every month.

We may ovulate consecutively for a few months and then stop ovulating for a couple of months, until one day the ovaries run out of eggs and stop ovulating all together when we enter menopause.

The gradual decline of ovarian function is a process called perimenopause. It can begin as early as age 35 and end at menopause when the period stops coming for 12 months.

The average age of menopause is 51 in the United States.

It’s interesting to note that the time we start menopause is highly correlated with our mother’s age at menopause. So low progesterone, the first step toward menopause, is also affected by the genetics. For further discussions, read:

Estrogen Dominance during Perimenopause

What Affects Estrogen Levels: Five Key Factors that Influence Your Estrogen Individuality

5. Progesterone Resistance

As discussed earlier, when the body has a high demand for cortisol, it makes less progesterone.

Not only that, an increased amount of cortisol in the body also competes with progesterone for progesterone receptors.

When progesterone cannot bind with a receptor because it’s blocked by cortisol, it cannot enter the cell to perform its functions.

As a result, you may also experience signs of progesterone deficiency even though your serum level is normal – a phenomenon called progesterone resistance.

6. Low Thyroid

The body needs adequate thyroid hormone to produce pregnenolone (the mother hormone) from cholesterol, which then makes progesterone.

So if you have an underperforming thyroid, your body may fail to produce sufficient progesterone as well.

And when the progesterone level is low, the brain will signal the thyroid to work harder to manufacture more pregnenolone.

This extra burden further weakens the thyroid, which will produce less pregnenolone (and less progesterone), creating a vicious cycle.

Learn the symptoms of a sluggish thyroid and what to do about it.

7. High Prolactin

Prolactin is a hormone in the pituitary that controls lactation in women. High prolactin suppresses the ovarian function, which reduces the secretion of progesterone and estrogen.

Higher levels of prolactin are normal during pregnancy and after childbirth during nursing.

However, certain illnesses and medication, as well as common stressors, can also raise prolactin level, causing progesterone level to be low.

These stressors include low blood sugar, strenuous exercises, physical discomfort, and emotional strain – basically anything that make your body and mind out of harmony.

Recommendations for Low Progesterone

When you encounter a problem, the first and most important step is to figure out what’s causing it. And when you identify the root cause, you’re in a better position to find effective solutions.

Here are my recommendations to get you started:

1. Determine if you have progesterone deficiency

First, ask yourself if you have signs of low progesterone. You may get a blood test to see if your serum level is low.

However, be aware that you may still experience signs of progesterone deficiency even when your blood test comes out normal. This could be due to estrogen dominance or progesterone resistance, per our discussion above.

2. Understand the causes

Next, study the causes of low progesterone and identify the most likely reason behind the imbalance you’ve been experiencing.

3. Find solutions

After you understand the possible causes, you can begin to explore and find effective solutions for example…

1. Learn natural ways to increase your progesterone level.

2. Address estrogen dominance and improve estrogen metabolism.

3. Build up your adrenal reserve.

4. Improve your thyroid function if you have an underperforming thyroid.

5. Get my complimentary guide on how to balance your hormones naturally.

4. Correct the root causes

These steps can help restore your hormone balance temporarily, but they often do not address the ROOT CAUSES of the imbalance.

And without correcting the ROOT CAUSES, your hormones can become out of balance again.

So if you’re really serious, you want to identify and address the ROOT CAUSES of the imbalance.

They often involve nutrition, lifestyle, as well as mental and emotional habits. The good news is that this is within our control and we can certainly do something about it.

Don’t let the pain of hormone imbalance weigh you down, let it become the catalyst for you to create some positive changes in your health – and in your life.

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