The symptoms of progesterone deficiency and hypothyroidism can be very similar. Being premenopausal, we know that her estrogen production was sufficient (if you are menstruating you have adequate estrogen). Because she still had regular periods, her doctor, like so many others, did not feel the need to test her progesterone level. He assumed that, despite her normal T3 and T4 levels, her fatigue and low basal temperature indicated hypothyroidism. He did not know that progesterone is anabolic (burns fat) and thermogenic (increases temperature) so that a deficiency causes weight gain and low temperature. He simply did not consider the possibility of progesterone deficiency.
Nevertheless, thyroid hormone is basic to all biological functions and that sometimes both thyroid and progesterone supplements are needed, as each has a promoting action on the other.
Without adequate thyroid, we become sluggish, clumsy, cold, anemic, and subject to infections, heart disease, headaches, cancer, and many other diseases and seem to be prematurely aged…. Foods aren’t assimilated well, so even on a seemingly adequate diet there is “internal malnutrition”. Irregular periods, often leading to needless hysterectomies, are common aspects of hypothyroidism; and breast disease, is another classic manifestation.
Estrogen (which we can try to balance with supplemental progesterone) inhibits the release of thyroid hormone from the gland, whereas an adequate amount of thyroid hormone, on the other hand, raises natural progesterone production and lowers estrogen. That makes it easy to see how thyroid hormone and progesterone can complement each other. He even made the interesting observation that since estrogen and cortisone weaken the blood vessels, progesterone (along with thyroid supplements) is a good way to help prevent easy bruising.
Estrogen dominance causes the liver to produce high levels of a protein called “thyroid binding globulin”, which, as its name suggests, binds the thyroid hormone and decreases the amount of thyroid hormone that can be assimilated into and utilized by the cells.
Thyroid Peroxidase is an enzyme in your thyroid gland; and it’s one of the enzymes you use to manufacture T4 and T3. So, if you don’t have good activity of this enzyme, then over time you’re just not going make enough T4 and T3. At some point, you’ll start suffering low thyroid symptoms such as:
How does progesterone play into this scenario? Well, normally, progesterone up-regulates TPO function.
Here’s what normally happens (a bit of physiology, here):
In the second half of the menstrual cycle, when she ovulates, there’s is surge of progesterone.
Well, when you don’t have enough progesterone, it’s pretty simple…TPO activity goes down and therefore, the amount of T4 and T3 you make goes down.
Here’s the key thing I want you to know about all this:
This is why a lot of times a woman will go to her doctor and be suffering low thyroid symptoms such as depression, hair loss, weight gain, high cholesterol, infertility, constipation, brain fog…
The doctor will run some kind of thyroid blood tests (usually woefully insufficient such as only a TSH and T4). The doctor says, “Looks pretty normal to me.” And if you have low progesterone as your hidden cause for your low thyroid symptoms…there’s not much the tests could pick up on lab work. Why?
Because when a woman is not making sufficient progesterone for her needs, it may not necessarily be reflected in an abnormal T4 or T3 or TSH that’s below or above the lab range on blood work. This is why low progesterone is definitely a hidden cause because the doctor that you are working with has to be able to recognize that you have got progesterone symptoms and low thyroid symptoms.
Many of these have to do with the menstrual cycle and getting pregnant so here they go:
If you have three or four of these symptoms…AND… and you’ve also got low thyroid symptoms, then low progesterone affecting thyroid peroxidase in your thyroid gland could be a HUGE factor for you.
What do you do about this progesterone-thyroid problem?
If you want to boil it down, you can have low thyroid symptoms and low progesterone symptoms that are ultimately being caused by unstable blood sugar levels. Blood sugar levels should be very stead…NOT up and down…peaks and valleys.
That’s a little bit beyond what we want to talk about today, but here’s the takeaway:
Synthetic progestins do not enhance thyroid hormone function; in fact, they make the problem worse. They occupy progesterone receptors and prevent real progesterone from its normal function.