Iron, Cortisol & Thyroid - Which is causing YOUR fatigue?
- Jun 4, 2025
- 3 min read
Updated: Nov 11, 2025
Still Tired? It Might Be More Than Just Iron or Thyroid.
Having low energy is such a struggle, and unfortunately one that I've personally struggled with. It affects your focus, your mood, your motivation, and it makes everything you have to do feel harder than it needs to be.
If you’ve been told your iron is "fine," your thyroid is "normal," or your labs don’t explain how drained you feel, it’s time to look at the bigger picture.
There’s a connection between low iron, low cortisol, and thyroid function that often gets missed in conventional care. Let’s talk about it.
Iron helps your body make cortisol
Your adrenal glands use iron to make enzymes that support healthy cortisol production. When iron is low, those enzymes slow down. That can leave you with low cortisol levels, especially under stress.
Cortisol also plays a role in digestion. When cortisol drops, stomach acid often drops too, which makes it harder to absorb the nutrients your body needs. Especially iron.
So now you're stuck in a loop: low iron makes it harder to produce cortisol, and low cortisol makes it harder to absorb iron.
Iron is also critical for thyroid hormone
You need iron for the thyroid peroxidase (TPO) enzyme, which helps your body make thyroid hormone. You also need iron to convert T4 into the active form, T3. Without enough, your body might be producing hormone but not activating it properly or not getting it into your cells where it’s actually used. This is one of the reasons people can be on thyroid meds, have "normal" labs, and still feel off.
But why is iron low in the first place?
Here’s where gut health comes in. You could be eating plenty of iron-rich foods but not absorbing them if:
You have low stomach acid, which is more common with stress, H. pylori, or low zinc
There’s inflammation in the gut that blocks absorption
You’re missing key cofactors like copper and protein
You’re eating foods or taking supplements that interfere with iron (like calcium or tannins in tea and coffee)
You need enough protein to make ceruloplasmin, a transport protein that moves iron through the body, plus you need bioavailable copper to activate that process. When one piece is off, the whole system can get jammed up.
Here’s the takeaway
If your energy is low and nothing seems to help, it's not just in your head and it's not just your thyroid. Iron, cortisol, and gut health are deeply connected, and when one gets thrown off, the others usually follow.
This is exactly what I walk you through in my Iron Deficiency Guide. It’s a simple, actionable resource with checklists, test options, nutrition tips, and supplement guidance to help you start restoring your energy in a sustainable way. This is full of advice I give every client who comes to me with iron deficiency.
It’s just $9 and available here:
Or, if you're ready for deeper support, fill out the contact form and we can talk about next steps.
If you like what you’re learning here, you’ll love the conversations happening inside my free Facebook group, Find Your Balance. Come join us!
My program Back to Balance: A Root Cause Roadmap for Healing Hashimoto's is made for women who are tired...physically tired and mentally exhausted from the gaslighting around thyroid health. Check out the video walkthrough below and grab the first module for free to see what it's all about.
If you're ready to start feeling better TODAY, click here!
Disclaimer: I do not diagnose, treat, prevent, or cure any disease or condition. Nothing I share with my clients is intended to substitute for the advice, treatment or diagnosis of a qualified licensed physician. I may not make any medical diagnoses or claim, nor substitute for your personal physician’s care. It is my role to partner with you to provide ongoing support and accountability in an opt-in model of self-care and any changes should be done under the supervision of a licensed physician.
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