In this episode, Dr. Eric Osansky concludes his 3-part hormone series by exploring the important relationship between progesterone and thyroid health. While estrogen often receives most of the attention, progesterone also plays a vital role in supporting thyroid hormone sensitivity, reproductive health, immune regulation, sleep, mood, and nervous system function. Dr. Eric explains why symptoms of low progesterone frequently overlap with both hyperthyroidism and hypothyroidism, making proper testing and individualized evaluation essential.
Dr. Eric discusses how chronic stress, adrenal dysfunction, thyroid imbalances, and hormonal changes during perimenopause and menopause can all contribute to lower progesterone levels. He explains the role progesterone plays in Graves’ disease, Hashimoto’s thyroiditis, fertility, anxiety, insomnia, and menstrual health, while also reviewing common testing options, including serum progesterone and the DUTCH test. Throughout the episode, he emphasizes supporting adrenal health, improving stress resilience, optimizing sleep, and addressing root causes before relying solely on hormone replacement whenever appropriate.
The episode concludes with practical recommendations for naturally supporting healthy progesterone levels through stress management, nutrition, targeted nutrients, and herbs such as Vitex, while acknowledging that bioidentical progesterone has an important place for some individuals. If you want a clearer, more balanced understanding of the thyroid-progesterone connection and how this hormone influences thyroid and overall health, you’ll get a lot out of this episode.
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Dr. Eric Osansky:
Let’s go ahead and discuss the thyroid-progesterone connection, starting with some common symptoms that overlap between thyroid imbalances and low progesterone. Fatigue is more common with hypothyroidism, low thyroid, but people with hyperthyroidism also can have fatigue, especially because hyperthyroidism puts a lot of stress on mitochondria, the energy powerhouses of the cell. Low progesterone can also cause fatigue.
Low progesterone can cause anxiety, which we commonly see in hyperthyroid and Graves’.
Low progesterone can lead to sleep disturbances, which is common in both hyper and hypo, maybe more common in hyperthyroidism because of anxiety. There can be other causes of sleep disturbances.
Brain fog is more common with hypothyroidism, not to say that those with hyperthyroidism can’t experience brain fog, but low progesterone can also play a role. Low progesterone can cause mood swings, which we see in both hyper and hypothyroidism. Irregular menstrual cycles are common with both types of thyroid hormone imbalances. Of course, progesterone plays an important role when it comes to having healthy menstrual cycles. Sometimes, it can be difficult to know if it’s low progesterone or hyper or hypothyroidism. That’s where testing comes into play, which we will talk about later.
What is progesterone? Progesterone is produced primarily by the ovaries after ovulation. When a woman is cycling, the ovaries are primarily producing progesterone. The adrenals also produce progesterone. Especially this is the case after menopause. The ovaries really don’t produce any more progesterone. Your adrenals do, in small amounts. You don’t need the same amount of progesterone in post-menopause as you do when you’re cycling. But you do want some progesterone.
The problem is a lot of people have stressed out adrenal glands, compromised adrenal glands, which will negatively affect progesterone production. There is a time and place for taking bioidentical progesterone. Even if you do this, you want to try to do everything you can to optimize the health of your adrenal glands. We will talk more about this.
As far as some of the key functions of progesterone, it supports a healthy menstrual cycle. It also helps prepare the uterus for pregnancy. You definitely need adequate levels of progesterone to have and maintain a healthy pregnancy. It supports sleep and relaxation, influences mood and brain function, and plays a role in immune regulation. Also, it’s important to balance out some of the effects of estrogen.
You need both healthy estrogen levels, healthy progesterone as well. Of course, all hormones, healthy cortisol, healthy testosterone, which I don’t think I’ll be doing a thyroid-testosterone connection episode any time soon, at least not as part of this series. Maybe in the future.
As far as the relationship between progesterone and thyroid health, progesterone may help improve thyroid hormone sensitivity. You might have heard of insulin sensitivity; when you have insulin resistance, you have too much insulin, so it won’t get into the cells.
I won’t get into thyroid hormone resistance, which is when you have too much thyroid hormone, so it won’t get into the cell. You need healthy progesterone to help with the sensitivity of the thyroid hormone receptors.
There are other functions, not necessarily related directly to thyroid health. Progesterone also is important for a healthy nervous system. The nervous system is important for healthy thyroid. The nervous system is important for all the bodily systems because the nervous system controls everything.
Progesterone has calming effects on the brain; influences what’s called the GABA receptors. GABA is a neurotransmitter. Definitely some overlap when it comes to this and thyroid but not directly affecting thyroid health in this way. It’s affecting the nervous system, which could affect the thyroid. The thyroid also could affect the nervous system.
Let’s talk about hyperthyroidism/Graves’ and progesterone. Then we will shortly talk about hypothyroidism/Hashimoto’s. Some of this has some overlap. I already spoke about things like irregular periods. When you have hyperthyroidism, shortened cycles are common. Missed periods. It’s not necessarily the hyperthyroidism directly affecting the cycles, but hyperthyroidism affecting the hormones. It could definitely affect progesterone levels, which could cause the shortened cycles, missed periods, irregular periods. In some cases, reduced ovulation.
Stress is a big topic when it comes to all the hormones. If you have chronic stress, that will affect thyroid, progesterone, estrogen, testosterone. We also have to think about the physical stressors of hyperthyroidism. Hyperthyroidism places a large demand on the body, a lot of physical stress. That stress also may affect ovulation as well as progesterone levels. It’s both the emotional stressors and the physical stressors that could have a negative effect on progesterone as well as estrogen, which I had a separate episode on. All the sex hormones, if you have chronic stress, it’s going to deplete the stress hormones.
When it comes to common symptoms of low progesterone in those with Graves’, looking at the overlap of hyperthyroid symptoms and low progesterone. I already mentioned some of these like anxiety, insomnia, mood swings. You might get other symptoms like heavy or irregular periods or shortened cycles.
Difficulty maintaining a pregnancy. That is an issue. If you have Graves’, you can have elevated TSIs, which will increase the risk of having a miscarriage. Also, the impact of hyperthyroidism on progesterone levels could make it difficult to maintain pregnancy, which is if you are looking to get pregnant, and you are dealing with hyperthyroidism, you really want to get the hyperthyroidism under control. If you have Graves’, you want to get the autoimmune response under control. That can take more time.
With hyperthyroidism, many women don’t want to take antithyroid medication. I understand. I didn’t take antithyroid medication when I dealt with Graves’. You don’t want to be pregnant and have unmanaged hyperthyroidism.
When it comes to Graves’, which is more of an immune system condition than a thyroid condition, progesterone also has immunomodulating effects. I mentioned this during the thyroid-estrogen connection episode, the importance of estrogen when it comes to the immune system. Progesterone also is important in modulating the immune system. It’s important to have a balanced immune response. You really need healthy levels of both estrogen and progesterone when it comes to having an optimal immune system.
When it comes to hypothyroidism/Hashimoto’s and progesterone. Thyroid hormones, very important. You don’t want it too high with hyperthyroidism, but you definitely don’t want it too low. Thyroid hormone affects pretty much every cell tissue in the body. Thyroid hormones influence reproductive function. Conception, too. If you have low thyroid and are trying to conceive, it will be very difficult to do so, especially if the levels are overtly low.
Many times, with hypothyroidism, you have subclinically low thyroid hormones, meaning that they’re within the lab range but not within the optimal range. In that case, it could still be difficult to conceive. If they are overtly low, like below the lab reference range, it could be even more difficult to conceive.
Thyroid hormone definitely plays a role in reproduction function. If you have low thyroid, it could contribute to irregular ovulation. It could also lead to reduced progesterone production, menstrual irregularities, which could be related to low thyroid hormone itself or low progesterone. You might see heavier periods, fertility challenges, irregular cycles. I see irregular cycles more in my hyper patients, but it could happen with hypothyroidism as well.
I mentioned some of these symptoms seen with both hypothyroidism and low progesterone. I mentioned fatigue. I didn’t mention depression. I mentioned anxiety with hyperthyroidism. You could also get depression. Progesterone is more calming; that’s why anxiety is common if someone has lower progesterone.
Sometimes, you’ll see depression. I mentioned brain fog, weight gain. That progesterone-estrogen balance is important to maintain a healthy weight. Of course, thyroid hormone is extremely important, too. If someone has low thyroid hormone, weight gain is common.
I mentioned sleep disturbances. There are other symptoms, but those are some of the more common ones.
If you have hypothyroidism and are taking thyroid hormone replacement, which there is a time and place to do so, there is a lot of issues with thyroid hormone. One is not everyone can convert T4 into T3. Unfortunately, most people, when they take thyroid hormone, are given synthetic T4. Time and place for this. A lot of people have problems converting T4 into T3. T3 is the active form of thyroid hormone, so you don’t want just to look at T4 or TSH. You want to look at an entire thyroid panel.
If someone is taking thyroid hormone, and their levels aren’t optimal, then you could work on conversion. In the meantime, you could look into alternatives such as desiccated thyroid, like NP thyroid or Armour. There is also a time and place for synthetic T3, like Cytomel.
Of course, you want to try to address the cause of the problem. If someone has Hashimoto’s, like Graves’, this is more of an immune system condition. The person might need to take thyroid hormone replacement. In some cases, they might need to take it long-term. You want to address the immune system component, that autoimmune component, and some people won’t need to take thyroid hormone permanently. Others might still need to take it long-term. The problem is most practitioners, especially conventional practitioners, medical doctors, endocrinologists, aren’t doing anything for the autoimmune component of Hashimoto’s or Graves’.
Progesterone, estrogen, and thyroid health. Again, I have that separate episode on the thyroid-estrogen connection, so I won’t get into great detail. I spoke about estrogen and thyroid and how estrogen influences and increases TBG. You have less free thyroid hormone because the free thyroid hormones bind to TBG. You get lower thyroid hormone availability.
Estrogen dominance can mean that you have too much estrogen or problems metabolizing estrogen, but also, if someone has normal estrogen levels and low progesterone levels, this is also considered to be a state of estrogen dominance. It’s not just about the estrogen levels. We also need to consider the progesterone levels as well.
Perimenopause/menopause. Progesterone often declines before estrogen. In post-menopause, you will get low progesterone and low estrogen. Like I mentioned earlier, the adrenals. For someone in post-menopause, they will never have natural levels of estrogen and progesterone of a 20, 30, or 40-year-old. You should have optimal levels for your age, which will be a lot lower than someone who is in pre-menopause. Time and place for bioidentical progesterone.
What I wanted to talk about here, there could be overlap between perimenopausal symptoms and thyroid symptoms as well. You could have fatigue, anxiety, brain fog, sleep disturbances, hot flashes, and night sweats, especially with hyperthyroidism. Someone might experience what seems like hot flashes but is more like heat intolerance or excess sweating. Estrogen is more closely associated with those hot flashes in those who are post-menopausal.
Remember, we could also have that estrogen dominance, where estrogen is looking good, but progesterone is low. This can also cause some of these symptoms. That’s why you don’t just want to look at one of the hormones. If you’re testing hormones, you want to look at progesterone and estrogen. Like I said, a lot of this comes down to adrenal health, too. Optimal adrenals, optimal thyroid, many times will lead to optimal sex hormones. Optimal for one’s age.
Let’s talk about testing. Blood testing is what’s most commonly recommended. You could certainly do serum progesterone. If you’re cycling, the timing definitely matters. Usually, you want to do it in the second half, the luteal phase. It depends on the cycle. If you have an average of 28-30 days for your cycle, you will usually collect the blood sample between day 18 and day 21. If you have a longer or shorter cycle, then you need to consider that. If you’re focusing on progesterone, you definitely want to collect the blood sample in the second half of the cycle.
If you’re post-menopausal, it doesn’t make a difference. If someone is a male listening to this, doesn’t make a difference.
One thing I don’t like about testing for progesterone in the blood is I am not crazy about the ranges. The ranges suggest that your progesterone could be 0, and that’s fine, at least post-menopause. In post-menopause, a lot of labs will have the range between 0-5, suggesting if someone’s progesterone levels are 0 or 1, that’s fine.
I like the DUTCH because it gives a good optimal range for post-menopause. When doing a DUTCH test, you can see if you’re within that post-menopausal range. I do see women who are below that post-menopausal range. If they are below that post-menopausal range, we want to figure out why. Is it the adrenals? If you do a DUTCH Complete, it will look at the circadian rhythm of cortisol. It will look at cortisol throughout the day, DHEA, and DHES.
It’s a little bit different. It’s looking at the progesterone metabolites, two specific ones. Based on those metabolites, it gives you a reading of total progesterone. It also looks at estrogen metabolites, cortisol, cortisol metabolites.
There is a time and place for blood. It’s definitely less expensive than a DUTCH test, but a DUTCH test is looking at more than just a simple blood test.
I am not suggesting everybody needs to do DUTCH testing. I don’t recommend it to all my patients. I do recommend adrenal testing to all my patients. You need healthy adrenals to have healthy sex hormones. Even if we just do an adrenal saliva test, and we see the adrenals are out of balance, that could be contributing to low progesterone, estrogen, or testosterone. We will want to address the adrenals. That is the case even if someone does choose to take bioidentical progesterone.
If you do choose to test the hormones, you might as well look at the different hormones, not just progesterone. You might as well look at the estrogens, at least estradiol and maybe estrone, the two main estrogens. Time and place for estriol. If someone is pregnant, you may look at estriol. The DUTCH test looks at all three anyway.
Free and total testosterone, DHEA. Cortisol. If you do a blood test, you will typically do a morning cortisol. You always want to do a full thyroid panel: TSH, free T4, free T3.
Reverse T3, I won’t talk about here because I do have other episodes where I discuss this. It’s the inactive form of T4. I don’t test it in hyperthyroidism because most people with hyperthyroidism will have elevated reverse T3 levels. If someone has hypothyroidism, you might want to look into testing reverse T3. The thyroid antibodies, of course, too.
As far as supporting healthy progesterone levels, we already spoke about some of the things you need to do. Healthy adrenals, healthy thyroid. Blood sugar imbalances also could play a role. Insulin is a hormone as well. Cortisol, thyroid hormone. All of these are important.
The real big focus is going to be on stress. Chronic stress will not only deplete the sex hormones but also will have an impact on the thyroid hormones. Trying to do as much as you can from a stress management perspective. If you could reduce your stressors, great. Many people can’t reduce their stressors. If that’s the case with you, you need to focus more on stress handling, even if it’s just five minutes a day to get into the routine of stress handling. I have spoken about this plenty. Then you can gradually increase the duration.
Sleep is very important. It’s a catch-22. When you have low progesterone, you might have issues sleeping. This is where maybe taking bioidentical progesterone can help, if progesterone is causing the sleep issues. Maybe you don’t want to permanently take bioidentical progesterone, even though some women do. You might be one who is a little bit hesitant. If you are only getting 3-4 hours, even five hours of sleep, and you or your practitioner suspects it might be related to progesterone, it might be a good idea to consider taking progesterone.
Other nutrients can help support progesterone production. Magnesium, Vitamin B6. There is an herb called Vitex, also known as chaste tree or chaste berry. That can help stimulate the body’s own production of progesterone. There is a time and place for that. If someone is going to take that, usually they will take it in the second half of their cycle for those who are cycling. Post-menopausal women could take it as well.
Keep in mind that post-menopause, it’s usually going to be the adrenals that are primarily responsible for progesterone production, so that’s why especially in post-menopause, you want to focus on adrenal health. Even in pre-menopause.
Just about everybody I work with deals with chronic stress. It doesn’t matter if someone is in their 20s, 30s, 40s, or older. Stress is usually a factor. In younger women, they have the advantage of producing more progesterone, so it might not have as big an impact as with someone who is in post-menopause, but it’s still a factor.
I’m not saying there is never a time and place for taking progesterone when someone is cycling. Regardless, if someone is cycling or in post-menopause, you want to try to do whatever you can to optimize adrenals. If you are cycling, you should be producing enough progesterone. If not, stress very well might be the reason.
That’s all I wanted to discuss here. Just wanted you to be aware of the importance of progesterone. Seems like a lot of podcasts these days focus more on estrogen. Even some of my podcasts. There are more podcasts that talk about estrogen and estrogen metabolism, how we deal with xenoestrogens. It’s common to talk about estrogens compared to progesterone.
I know I have at least one episode with Dr. Betty Murray, who spoke about progesterone a few years ago. That might have been the last episode that focused on progesterone. I have had numerous women talk about the sex hormones, progesterone and estrogen. Seems to be more of an emphasis on estrogen lately.
Both hyperthyroidism and hypothyroidism, high thyroid and low thyroid, Graves’ and Hashimoto’s, can play a role with progesterone imbalances. A lot of overlap of symptoms when it comes to the thyroid and progesterone. I mentioned progesterone influencing things like sleep and mood and immune function. Reproductive health.
The #1 takeaway when it comes to the three episodes—the thyroid-cortisol connection, the thyroid-estrogen connection, and the thyroid-progesterone connection—is stress is a big factor with all three of these connections. Cortisol is an adrenal hormone, but that thyroid-cortisol connection can without question affect the thyroid-estrogen and thyroid-progesterone connections.
If you are doing everything you can from a stress management standpoint, and your hormones remain low, then maybe you do need to take bioidentical progesterone and/or estrogen, especially if you are in post-menopause. I am not saying there is never a time and place, but most hormone doctors will prescribe progesterone, estrogen, testosterone to all of their post-menopausal patients.
Again, I am not saying that’s wrong. That’s their approach. I am definitely open-minded. I am still at the point where I don’t feel like every single woman in post-menopause needs to take bioidentical hormones. We could say there are other reasons, like bone health, which is important. It comes down to testing.
If you are in post-menopause and are doing a DUTCH test that has really good post-menopausal ranges and are within the post-menopausal range. If you’re not, work for a few months on getting those levels up. Try getting within the post-menopausal range. If that doesn’t happen, maybe consider bioidentical progesterone or estrogen or testosterone. This isn’t a recommendation not to take bioidentical hormones, but to make sure you pay attention to the health of the adrenals since they have such an important role when it comes to having healthy sex hormones.
Hope you found this solo episode to be valuable. Thanks so much for listening. Look forward to catching you in the next episode.