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Is Low Progesterone Affecting Your Thyroid|

Is Low Progesterone Affecting Your Thyroid. Hypothyroidism is affected by many things including a progesterone deficiency. What makes this more complex and difficult for so many doctors is the fact that the symptoms of low progesterone overlap with the symptoms of low thyroid. Let me share a quick story with you.

About 6 months ago I began working with a woman who was diagnosed with hypothyroidism, she was being treated by her primary care doctor with Synthroid but still complained about fatigue, hair loss, brain fog, depression, insomnia and weight gain- essentially she still experienced all symptoms of hypothyroidism yet she was on medication and her TSH levels were normal.

We began to go through her history and being in her 40s we began to think about some of the other potential causes to these unresolved thyroid symptoms.

She was having regular cycles however she experienced many PMS symptoms. She had breast tenderness, she experienced changes in mood, she had brain fog, she had menstrual cramps, she had water retention and many of her symptoms intensified- they got worse just before her period.

Her primary care doctor told her that her thyroid levels were good and so he wanted her to go on antidepressants and put her on a birth control pill. She didn’t like this idea, she wanted to approach these problems using a Holistic Functional Medicine approach, so  she contacted me.

Heres What We Did

Full thyroid panel (which she had never had done) we looked at her TSH levels, Total T3, Free T3, total T4, Free T4, reverse T3, thyroid antibodies and her Thyroid binding globulin levels- up to this point, her primary was only running a TSH) at the same time we were running those tests we also ran testing on her adrenals and we ran a 28 day dynamic hormone mapping test.

28 day Dynamic Mapping test- essentially maps out the fluctuations in your hormones (estrogen and progesterone) throughout your entire cycle it also gives us an average of the testosterone levels.

We uncovered that she had low T3 and low free T3 levels, She had elevated reverse T3, she had low DHEA and Cortisol (indicating an adrenal hormone imbalance) and we found she had low progesterone levels. Now….These hormone imbalances  are some of the most common hormone imbalances seen in woman in their 40s.  It’s also the most common reason for low progesterone. If you don’t ovulate, you don’t make progesterone. Now here why progesterone is so important to the thyroid.

Progesterone Levels Affect Your Thyroid

Progesterone and thyroid hormones have a reciprocal relationship. What that means is that you need adequate amounts of thyroid hormone for your ovaries to make progesterone and you also need adequate amount of progesterone for optimal thyroid function.

Low Progesterone Causing Your Thyroid Disease

Progesterone Deficiency Can Affect Thyroid Hormone Production

Research shows us that  shows that A progesterone deficiency causing depression of the enzyme called thyroid peroxidase (TPO). Normally progesterone up-regulates TPO function. Thyroid Peroxidase is an enzyme in your thyroid gland; and it’s one of the enzymes you use to makeT4 and T3 thyroid hormones.  So, if your TPO enzyme is depressed and is not active, then over time you’re just not going make enough T4 and T3.

But that’s not all progesterone does. Progesterone also affects your Thyroid binding globulin levels (TBG) and this is why measuring your TBG levels is important. If you have been watching my YouTube videos for any length of time, in many videos I have talked about the importance of Thyroid binding globulin (TBG) in relationship to normal thyroid function.

In a previous video, I talked about how birth control pills and hormone patches (both of which) are high in estrogen will increase the levels of TBG and that this is not a good thing because high levels of TBG bind up all your T3 levels and as a result you end up with all the symptoms of hypothyroidism despite a normal TSH.

Well it turns out that with a Progesterone deficiency you will often have elevated TBG levels in the blood.  so that less thyroid hormone can be free and get into the cells.

But if you are low in progesterone- you will have lower levels of these protein carriers (TBG) and now you end up with less T3 and T4 thyroid hormones getting into cells.

Alright so there you go, if you have been wondering if your hormones can affect your thyroid gland you now know that low progesterone can cause low thyroid either by affecting TPO levels or by affecting Thyroid binding globulin levels.

What Do You Do About This Low Progesterone-Thyroid Problem?

There are a few reasons for low progesterone that need to be understood before resorting to progesterone replacement. I will tell you that I don’t believe in putting every woman who has low progesterone on progesterone replacement and that’s because there are a number of reasons why the progesterone could be low. Just because a patient has low thyroid hormone does not automaticlay make them a candidate for thyroid hormone replacement, the same hold true for woman with low progesterone. We need to stop treating patients with this oversimplified approach whereby, if one hormone is low we just give that hormone. We need to understand “WHY” the hormone is low in the first place. This is what Functional medicine is all about, we need to know the mechanism!

Causes of Low Progesterone in Woman With Hypothyroidism

Is Low Progesterone Affecting Your Thyroid.

Non ovulatory cycle-

Remember what I said in the beginning of the video- If a woman doesn’t ovulate, she won’t produce progesterone. If this is the case you need to find out why ovulation is not taking place.

Inflammation/Oxidative Stress-

Inflammation is detected throughout many normal reproductive progressions, for the duration of ovulation, menstruation, implantation, as well as parturition. Ovulatory cycle is also considered as inflammatory process because the rupturing of dominant follicle undergoes the process of healing. However chronic excessive inflammation will affect Fertility.

One contributor to increased inflammation can be elevated levels of oxidative stress. This is also true for increased oxidative stress promoting inflammation, so it is a bit of the chicken and egg scenario. Either way, inflammation and oxidative stress are inextricably linked.

Oxidative stress is happening within the body all the time. Reactive oxygen species that cause oxidative stress are necessary for many biological processes (processes within the body) but just as the name sounds, these reactive oxygen species are unstable. If levels rise too much, or there is a reduction in the defense systems used to combat reactive oxygen species (eg. antioxidants), they can cause considerable damage to DNA and cell membranes, leading to cell death.

Estrogen Dominance

Estrogen dominance occurs when estrogen levels are abnormally high in relation to progesterone. This doesn’t necessarily mean that progesterone levels are normal and estrogen levels are higher; sometimes abnormally low progesterone levels can cause estrogen dominance.

Symptoms of Estrogen dominance include cellulite, breast or ovarian fibroids, varicose veins, weight gain around your hips, and issues like painful periods, bloating and mood swings.

Stress/Adrenal gland-

Chemically speaking, when cortisol (our stress hormone) increases, it blocks progesterone receptors and limits the activity of progesterone. Chronic stress is also a big contributor to progesterone levels. When your body is stressed, it works to produce higher levels of the hormone cortisol which manages stress in your body.

Because progesterone is the precursor to cortisol, when cortisol levels increase, progesterone levels decrease. So, too much stress in a woman’s life can lead to a progesterone deficiency, causing the estrogen dominance symptoms mentioned above.


Low protein intake, low Fat diets, zinc deficiency, B2, B6,12, folate deficiency, magnesium, vitamin C. These are just some of the vitamin deficiencies seen in low progesterone.

Most oral contraceptives are made with combinations of synthetic estrogen and progestin, a synthetic form of the hormone progesterone. After taking the pill, these synthetic hormones enter the brain and act as endocrine disruptors, interfering with the signaling process that is necessary for ovulation. In particular, they prevent the hypothalamus from signaling to the pituitary gland (which regulates your hormones) to secrete the hormones that cause an egg to be released. In the unlikely event ovulation does occur and an egg is fertilized, the synthetic progestin thins the uterine lining, making it more likely that the egg will be shed.

Polycystic ovary syndrome (PCOS).

PCOS causes a hormone imbalance, which affects ovulation. PCOS is associated with insulin resistance and obesity, abnormal hair growth on the face or body, and acne. It’s the most common cause of female infertility and is often accompanied by Insulin resistance.

Women with PCOS show chronic low-grade inflammation, characterised by increased plasma levels of inflammatory cytokines, which have been associated with insulin resistance. Levels of oxidative stress are also increased in PCOS. Circulating levels of antioxidants, which are our defence against oxidative stress, are also lower.

Hypothalamic dysfunction.

Two hormones produced by the pituitary gland are responsible for stimulating ovulation each month — follicle-stimulating hormone (FSH) and luteinizing hormone (LH). Excess physical or emotional stress, a very high or very low body weight, or a recent substantial weight gain or loss can disrupt production of these hormones and affect ovulation. Irregular or absent periods are the most common signs.

Premature ovarian failure.

Also called primary ovarian insufficiency, this disorder is usually caused by an autoimmune response or by premature loss of eggs from your ovary (possibly from genetics or chemotherapy). The ovary no longer produces eggs, and it lowers estrogen production in women under the age of 40.

Too much prolactin.

The pituitary gland may cause excess production of prolactin (hyperprolactinemia), which reduces estrogen production and may cause infertility. Usually related to a pituitary gland problem, this can also be caused by medications you’re taking for another disease.

Xenoestrogens-aka endocrine disruptors

So these are things worth considering under this umbrella of “I have low progesterone” this is also why I cant say take this because you have low progesterone or take this because you have low thyroid. To be successful with treatment, you need to know what the cause of the problem is.

My best advice is to work with a functional medicine doctor who understands this, someone who thinks outside the low progesterone/low thyroid replacement box and someone who can properly test you and investigate your Big Picture- (The reasons for low progesterone/Low Thyroid)

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