Ep. 82 How the Thyroid Changes in Perimenopause — What You Notice First & Why Proper Testing Matters

Is it perimenopause… or your thyroid?

In your late 30s and 40s, symptoms like weight gain, fatigue, brain fog, and hair thinning are often blamed entirely on hormonal shifts.

But the thyroid is deeply connected to what’s happening during perimenopause — and it’s frequently under-tested and misunderstood.

In this episode, we break down how thyroid physiology changes in perimenopause, the early warning signs women notice first, and what can happen when testing is incomplete.

Because “normal labs” don’t always mean optimal function.

In This Episode, We Cover:

• How estrogen and progesterone shifts impact thyroid function
• Why stress and cortisol interfere with thyroid hormone conversion
• The difference between T4 and T3 (and why it matters)
• Early thyroid symptoms that overlap with perimenopause
• How under-eating and overtraining can suppress thyroid output
• Why testing only TSH often misses the full picture
• The role of thyroid antibodies in autoimmune thyroid disease
• What can happen metabolically if thyroid shifts go unaddressed

If you’re ready for personalized metabolic and hormone assessment, learn more here:

🔗 www.tracyerinwellness.com

Perimenopause isn’t the beginning of decline.

It’s a phase that requires more precise strategy. 💛

Transcript

Speaker 2 0:09

Welcome to the Balance Hormone Solution podcast. If you're a woman 35 plus feeling exhausted, struggling to lose weight, and wondering where your libido went, this is for you. I am Tracy Aaron, a functional medicine practitioner who helps women balance their hormones naturally without prescriptions, guesswork, or trendy nonsense. 'Cause here's the truth: your symptoms aren't random. They're signals, and if you know how to listen, you can fix the root cause and start feeling like yourself again. If you're ready for real solutions, let's get to it.

Speaker 0:50

Welcome back to The Balance Hormone Solution, and today we're talking about something that gets missed constantly in women in their late 30s and 40s, and that's thyroid changes. Thyroid changes in perimenopause are quite common because this is what's happening. The woman maybe starts gaining some weight. She starts feeling more exhausted. Her hair is thinning, falling out in clumps in the shower. Her anxiety is higher. Her periods begin changing. And guess what? She's told, "Hey, you're getting older. It's just perimenopause. Don't worry, your labs are normal." But sometimes it really is her thyroid, or more specifically, it's how the thyroid and perimenopause interact with each other. So today on the podcast, I wanna break this down. This entire intersection is going to make more sense to you here in a couple minutes. So first, why is a thyroid more sensitive in perimenopause than any other time of your life? Well, perimenopause is not just about estrogen declining. If you open Instagram, that's what you think it is. You think it's just estrogen decreasing over time and making you BSC, right? Batshit crazy. But no, it's not just about estrogen declining. There's a lot going on inside the body. And if we're gonna talk about estrogen in particular, it's more about the fluctuation of estrogen than it is the overall decline. But that estrogen, it is gonna rise and fall unpredictably. You can't control whether or not it's high or low on this day or that day. Progesterone's gonna decline first, okay? That's your, your hormone, your calming hormone that's going to make you feel more stable moods, peaceful at night, not wanting to rip everybody's head off. That is what's declining first. And at this time of life also, your cortisol is starting to shoot high, increase, go through the roof, and sleep will just shift and become a little bit lighter, less deep sleep, less quality sleep. Your overall hours might stay the same, but it's really about that 3:00 AM waking. What is going on with that? I did a podcast on that a couple weeks ago. Go back in time if that's something that you're struggling with. But your thyroid is really sensitive to everything that I just mentioned, that estrogen fluctuating, the progesterone declining, the cortisol increasing, sleep becoming lighter. Our nutrition often changes at this time. So thyroid is picking up on all of this. It's paying attention, and it's starting to notice all of these minute and fragile delicacies of the body. So estrogen... It's gonna influence something called thyroid-binding globulin. Now, this is going to affect how much thyroid hormone is actually available to your cells, right? This makes sense, right? It's like it- it's going to bind the thyroid from getting where it needs to go inside the body. Estrogen's going to influence that. You can imagine what's going to... how that's going to impact the rest of your body if your thyroid is beginning to bind estrogen, right? Progesterone, supporting that metabolic calm, sleep. Th- that's critical for thyroid conversion. We need to switch hormones from one form into another form in order for the body to use it. Progesterone is a part, a big player in that. Cortisol directly is going to impact this conversion that I just mentioned between T4 and T3. T3 is your active thyroid hormone. So during pen- perimenopause, even if your thyroid gland isn't, let's say, failing, the environment around it is definitely shifting, and that alone can create symptoms. So let's talk about those symptoms. Like, what symptoms show up first? Well, here's where it gets tricky. I mean, early thyroid shifts in perimenopause, they do... they often look like, quote-unquote, "normal aging," right? First thing that women notice would be things like just subtle weight gain, right? You're, like, eating well, you're exercising, but, like, you're just starting to put on pounds a little bit easier, so it's more difficult to lose weight. You maybe have increased fatigue that sleep doesn't touch. Feeling just a little bit colder than usual, or this is really, really common with thyroid disorders, constipation. Hair thinning, the outer eyebrows. Are you finding yourself that you need to use an eyebrow pencil more often or darker colors to fill that eyebrow in more? Maybe that's your thyroid, right? Dry skin, brain fog, lower motivation, or even heavier or more irregular cycles. Sounds a lot like what we talk about for perimenopause, right? But here's the confusing part Some women get dismissed when they go to their doctors because those sound so much like just, quote-unquote, "regular perimenopause symptoms," your doctor just says, "Well, it is just part of getting older. It's part of the natural and normal hormonal shift." But when thyroid function slows, even mildly, metabolism begins to slow, and that is going to amplify every other perimenopausal symptom that you experience. So le- let's dive a little bit deeper and talk about the physiology, like, what's actually happening physiologically, and I wanna talk about three main patterns that I tend to see. Number one would be a reduced conversion, right? I mentioned that we need to turn T4 into T3, okay? T4 is your storage hormone. Body doesn't really use it. It cannot be applied and effective in the body. We store T4. T3 is the active hormone, okay? So we have to turn T4 into T3 in order to be able to use the thyroid hormone. Things like stress, inflammation, nutrient deficiencies, sleep disruption, all of these are common in perimenopause, right? Those alone reduce conversion of T4 to T3. So your TSH on your blood lab might look normal, but your active thyroid at the tissue level might be low because of this conversion, uh, is reduced. So you might feel sluggish, but you're told you're fine. Okay, number two common reason would be something called an increased amount of reverse T3. So when cortisol is chronically elevated in the body, your body can convert T4, not into T3, but reverse T3, which is a inactive form. This is, like, protective in high-stress states. Remember, your body's always trying to keep you alive, okay? So in high-stress states, your body can take that T4, not use... not turn it into the usable form of T3, but turn it directly into reverse T3. When reverse T3 is higher, it's going to lower the metabolic output overall. So if you're undereating, over-training, chronically stressed, not sleeping, you end up suppressing thyroid function without having true thyroid disease, okay? All coming back to that cortisol. The third pattern that I see is something that I'll call autoimmune activation. Now, there is hypothyroidism, and there is hypothyroidism with an autoimmune component to it. Those are completely different things in the body, and we treat them differently. So Hashimoto's would be the term for hypothyroidism with an autoimmune component. And so that, that disease process, it, it generally emerges or it's goes often undiagnosed for a very long period of time and worsens somewhere in the late 30s, early 40s. Okay? So why is this? Well, your immune system begins to shift, hormones begin to change, stress load changes with the demands of your life, right? And if the antibodies aren't tested, this goes undetected for years, and there's quite a bit of lifestyle things that... and nutrition things that we can do to reverse these numbers and to take us out of this autoimmune attack. And if we don't know, we don't know, and we continue the damage. And the damage with the thyroid happens to be mostly irreversible. So we want to know whether or not the immune system is involved with low thyroid, okay? And there's a testing problem with this. So this is the part that frustrates me the most. Like, most providers, they're really only gonna test TSH. TSH, thyroid-stimulating hormone, it's a signaling hormone from the brain, right? It's not telling you how much T3 you have in the body and is active. It's not telling you how well you're converting it. It's not telling you whether or not you have antibodies or an autoimmune disorder. It's not telling you whether inflammation is interfering and you've moved it into a storage hormone. You could have a normal TSH and still have, right? Low free T3, elevated antibodies, be poorly converting, highly symptomatic. And if we don't test it properly, women are just told your TSH looks good. The problem is, is the range that they're looking for is so wide everybody looks good, and that's a problem. So women end up blaming themselves, right? They'll diet harder, train harder, restrict more, and that makes thyroid suppression even worse. The low-carb craze didn't do any favors for our thyroids So what happens if we end up missing it, but it's actually there? If the thyroid shift goes unaddressed for a long period of time, then weight, that weight gain that we're all annoyed by becomes harder to reverse. Not impossible, just becomes harder. We have more obstacles. Our cholesterol eventually rises. The fatigue that was just every once in a while or just in the afternoon becomes chronic. Mood symptoms, worse. Muscle mass begins to decline faster despite lifting weights, and insulin resistance begins to increase. So because metabolism is slowing, belly fat in perimenopause becomes even more stubborn. And all these things have a compounding effect. One begets the next one, and it becomes a domino effect where here we are years down the road and just starting to uncover things, and if we had just looked at the complete thyroid, we wouldn't be where we are. So let's talk about that. What should be tested? Okay, at minimum, a full panel, blood panel. You're gonna test your thyroid through blood, okay? At, at minimum, a full panel should include not just your TSH, but free T4, free T3, and two antibodies. We're looking for TPO and thyroglobulin antibodies. That's bare minimum. I also love to add reverse T3. On top of that, I wanna know what's going on with the ferritin, what's going on with vitamin D, where is cholesterol, triglycerides, selenium status? Because thyroid function, just like anything else in the body, it's not isolated. And because it's influenced by stress, inflammation, and nutrient status, we wanna do regular testing and stay on top of this. So the big takeaway here is that not every symptom in perimenopause is just hormones, right? And not every thyroid issue requires an endocrinologist and medication. Now, sometimes we need to regulate our stress better, have adequate calories and protein consumption- bring those carbs back into the diet. Micronutrients are, are, you know, becoming depleted. We need to take a real good look at what we're eating. We need to restore our sleep, and sometimes we do need strategic hormone support. But ultimately, we cannot address what we don't measure. So if you feel like your body's slowing down in a way that just feels disproportionate, you might be doing everything right, nothing's moving, your labs are called normal, you don't feel normal, this is your sign to look deeper. 'Cause perimenopause alone, it's not breaking your metabolism. It does change the environment that your thyroid operates in, though, and when you support that environment properly, everything begins to feel more stable. Okay, so this is the hormone cascade that we like to talk about. So I hope this made sense. This is a big topic. There's so much to cover here, but I'll see you next time on The Balanced Hormone Solution.

Speaker 4 13:33

That's it for today's episode of The Balanced Hormone Solution podcast. If this resonated, don't just listen, do something about it. Make sure to subscribe so you don't miss what's coming next, and if you know another woman who's tired of feeling like a stranger in her own body, send her this way. For more support, check out the show notes. I've got resources to help you get started. Just remember, your body isn't broken. You just need the right tools. See you next time