Estrogen is the most well known female hormone, for the sake of simplicity, we could draw the analogy that progesterone is her lesser known sister.

Progesterone, while it may be less well known, is underrated. Progesterone plays an integral role in every woman’s menstrual cycle, fertility and how she may feel on a day-to-day basis.

Low progesterone symptoms have the ability to create a whole host of negative physical and emotional side effects. In this article, we will tell you everything you need to know about low progesterone including symptoms, causes, treatment and when to test.

Low Progesterone Symptoms | Your Guide

What Is Progesterone?

Progesterone is a female sex hormone. Progesterone belongs to a group of hormones called progestins and is often referred to as the “pregnancy hormone.”

That definition may sound super scientific or confusing, I know that before I started working with LetsGetChecked, I had a very limited understanding of what my hormones do. Trust me when I say, it takes time to understand what your hormones are doing during each cycle, alongside their overall significance! So, before we fully answer the question of “what is progesterone?” - let’s define hormones and how they fit into your menstrual cycle and indeed your overall well-being.

Defining Hormones

Hormones are the body’s “chemical messengers.” They are produced in different locations in the body, and collectively make up the endocrine system. Hormones travel through the body and stimulate a multitude of different activities.

As we have said, hormones stimulate activity in the body. In other words, hormones control the functions of different organs in the body and play a vital role in maintaining water-salt balance and how we expend energy.

The reason maintaining hormonal balance is so important is because a small variation in hormone levels has the ability to trigger significant responses in the body.

In breaking down the above definition, we would say that progesterone is the “chemical messenger” that travels through the blood to tell the body to ovulate. Progesterone tells the uterus (womb) to start building up the uterine lining so the fertilized egg may have a nest in which to implant and tells cervical mucus that it’s time to thicken following successful implantation of a fertilized egg.

Progesterone plays its biggest role during the second half of the female menstrual cycle and during pregnancy. It also plays a part in regulating our mood, sex drive, weight and water-salt balance.

Progesterone is produced in the corpus luteum during the menstrual cycle. The corpus luteum is a cluster of cells that form in the ovaries. The corpus luteum produces progesterone which regulates the rise and fall in thickness of the uterine lining.

In instances of successful pregnancy, the corpus luteum will continue to produce progesterone until a fetus is 7-9 weeks old. After this point, the placenta takes over the role of progesterone production.

Role Of Progesterone During The Menstrual Cycle

  • During ovulation, usually on day 14 of your cycle, the corpus luteum is formed.
  • The corpus luteum releases progesterone, and small amounts of estrogen.
  • The volume of progesterone rises in your blood.
  • Progesterone stimulates the thickening of the uterine lining ahead of potential implantation of a fertilized egg.
  • Progesterone ensures that menstruation does not occur during the window of opportunity for fertilization.
  • Progesterone disallows uterine muscle contractions that would cause the body to reject the egg.
  • If the egg is not fertilized the corpus luteum breaks down. This leads to lower volumes of progesterone and the shedding of the uterine lining, or in other words, the beginning of your menstrual cycle.


Role Of Progesterone During Pregnancy

  • In the instance of successful fertilization, the corpus luteum will continue to produce progesterone.
  • Progesterone stimulates the growth of blood vessels which continue to supply the lining of the womb.
  • The thickening of the womb continues during this stage of pregnancy and this lining will secrete nutrients for the growing embryo.
  • Progesterone plays a vital role in the growth of the placenta and the embryo.
  • Between weeks 8-12 of pregnancy, the corpus luteum breaks down and the placenta begins to take over progesterone production.
  • At this point, progesterone, released by the placenta, stimulates the enlargement of maternal breast tissue, strengthens pelvic muscles and prevents early lactation (breast milk production).


Role Of Progesterone In Day-To-Day Functioning

  • Progesterone plays a role in regulating blood sugar levels
  • Progesterone aids the body in using fat for energy
  • Progesterone acts as an antidepressant
  • Progesterone regulates blood clotting
  • Progesterone maintains libido
  • Progesterone facilitates the function of thyroid hormones
  • Progesterone protects from endometrial cancer and in some cases the onset of breast cancer


What Are The Symptoms Of Low Progesterone?

The symptoms associated with low progesterone are magnified by estrogen dominance, which often occurs in the absence of sufficient progesterone levels.

Estrogen dominance is a condition that occurs frequently when the delicate balance between progesterone and estrogen is disrupted.

Low progesterone, coupled with higher estrogen levels may lead to:

Low progesterone symptoms, coupled with higher estrogen levels may lead to:

  • Headaches
  • Bloating
  • Hot flashes
  • Breast tenderness
  • Weight gain
  • Fatigue
  • Difficulty concentrating
  • Insomnia
  • Decreased sex drive/libido
  • Increased intensity of PMS (premenstrual syndrome) symptoms
  • Irregular periods
  • Depression
  • Mood swings


Progesterone is produced in the ovaries and released into the bloodstream via signals of corresponding hormones.

What Causes Low Progesterone Levels?

There are a number of variables that can contribute to a reduced level of progesterone and low progesterone symptoms.

As we get older, the volume of certain hormones in our blood begins to decline. A woman's estrogen and progesterone levels begin to drop off as they age. From 35 years of age, estrogen begins to decline steadily, while progesterone will begin to decline more rapidly.

Chronic stress refers to an extended period of time where the mind or body is overwhelmed. If you are experiencing chronic stress, your body works hard to cope with this, in doing so, the production of cortisol, a stress hormone is increased. High cortisol in the body may lead to a progesterone deficiency.

Ovary/Ovulation issues
If you are experiencing issues with ovulation or have a condition that affects the function of your ovaries, you are more likely to suffer from low progesterone. Low progesterone may also interchangeably lead to issues with ovulation. This is the reason that a progesterone test is often used to measure ovulation function.

As the menopause starts,a number of hormones are thrown off balance. Perimenopause is translated as “around menopause”, it is the period of time coming up to a woman's last menstrual period when hormonal changes are taking place, and this can span across a number of years.. It is common for menopausal women to experience lower levels of progesterone, which often translate into physical symptoms that include mood changes, breast tenderness, weight gain, insomnia and thyroid issues.

How Can I Increase My Progesterone Levels Naturally?

To find out more about how to increase your progesterone levels naturally, read our recent article: How to Naturally Increase Your Progesterone Levels Without Pills And Supplements

How Can I Check My Progesterone Levels At Home?

You can test your progesterone levels from home with a simple blood test. Progesterone tests may be recommended during your menstrual cycle to monitor ovulation function and often as an overall health screen to identify the potential cause out any day to day symptoms.

Progesterone tests are also recommended during pregnancy to monitor the growth of the placenta and during the menopause to explain certain symptoms.

The LetsGetChecked Progesterone-Ovulation test monitors progesterone levels on Day 21 of your menstrual cycle. By examining progesterone in the blood, the test can decipher whether you are ovulating normally.


So, when should you check your progesterone levels at home?

You should consider testing your progesterone levels at home if you have been experiencing the following symptoms for over two weeks:

  • Headaches
  • Bloating
  • Hot flashes
  • Breast tenderness
  • Weight gain
  • Fatigue
  • Difficulty concentrating
  • Insomnia
  • Decreased sex drive/libido
  • Increased intensity of PMS (premenstrual syndrome) symptoms
  • Irregular periods
  • Depression
  • Mood swings

You should consider testing if:

  • You are trying to get pregnant
  • You have irregular or painful periods
  • You have been diagnosed with endometriosis
  • You have been diagnosed with polycystic ovary syndrome (PCOS)
  • You are going through the menopause

The test must be taken fasted, before 9 a.m and returned on the day of taking the test. Take the test on Monday, Tuesday or Wednesday for fastest results.

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If you are experiencing the symptoms associated with low progesterone or you are worried that you may have low progesterone levels, you can contact us directly via live chat to talk through your options.

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Read: How to Naturally Increase Your Progesterone Levels Without Pills And Supplements

Written by Hannah Kingston | Medically Approved by Dr. Susan O' Sullivan