Last Updated on June 5, 2026 by Deliciously Organic Editor
Is your body underconverting thyroid hormone? Are you producing enough T4, but not enough T3? The good news is that there are simple solutions for this! Let’s walk through my top 12 ways to improve thyroid hormone conversion (fT4 to fT3) naturally.
How does the thyroid make fT3?
Your thyroid produces fT4 and sends most of it to the liver to be converted into the active form, fT3. fT3 is the thyroid hormone that goes to every cell of the body.
If you’re under-converting, then you don’t necessarily have a thyroid problem, instead, you need to support your body so that it can make the conversion.
Where does the conversion of fT3 to fT4 happen?
The thyroid makes fT4 and sends most of it to the liver and then some to the gut, brain and peripheral tissues to be converted into fT3.
Since the liver takes on a large load of the conversion, supporting the liver is where I’ve found to be the best place to start when working with clients.
Due to the toxins we are exposed to on a daily basis from our food, air, water, body care, skincare, cleaning products, etc. it’s very common to struggle with liver congestion. If the liver cannot function properly, this can cause or contribute to low fT3. It can also cause estrogen dominance, severe headaches, blood sugar imbalance, chemical sensitivities, skin issues, and dark circles under the eyes, among other things.
As a Functional Nutritional Therapy Practitioner, I see this all the time, but the good news is there are some easy steps you can take to improve thyroid conversion.
The second most common reason for low fT3
If the body is under stress, then instead of fT4 being converted to fT3, it will be converted to reverse T3.
fT3 is the gas pedal of the body and rT3 is the breaks. So, if we have low fT3, we want to check our rT3 level so we can know if the low thyroid hormones are from stress.
Here are 12 ways to help improve thyroid conversion (fT4 to fT3):
1. Do a castor oil pack over your liver 3-4 times a week. As mentioned above, one of the major organs that takes care of fT4 to fT3 conversion is the liver, so it can be very helpful to support the liver with castor oil packs.
Here are instructions on how to do one, the supplies you’ll need and more about how they help the liver.
2. Eat a low-sugar, whole foods, nutrient dense diet.
One of the best things you can do for your body to increase your fT4 to fT3 conversion is to avoid processed foods and eat a nutrient-dense diet! Because the liver is responsible for filtering and neutralizing so many of the toxic substances we consume through our diet – alcohol, chemicals, excess hormones, and more – the cleaner we eat, the less load we put on our liver.
Keeping sugar intake around 20-30 grams or lower per day is important for optimal liver health. Too much sugar in the diet can actually lead to fatty liver disease and some studies show that sugar can be as damaging to the liver as alcohol.
The liver works with the pancreas and adrenals to keep blood sugar balanced in the body. If you struggle with blood sugar balance, it’s a good idea to take steps to correct this as it can have negative effects on the liver. See this article for more support on How to Balance Your Blood Sugar Naturally.
Please note that 20-30 grams of carbs does not include carbohydrates from healthy sources such as vegetables, soaked grains, raw dairy, etc.
3. Rub one drop of Zendocrine essential oil blend over your liver twice a day. I personally use it every day. It’s a blend of tangerine peel, rosemary leaf, geranium flower/leaf, juniper berry, and cilantro herb essential oils. It’s an amazing blend to add to your daily regimen to support the liver.
A little side note: I was on a real food diet for many years, and despite all of my efforts I would still get a break out on my chin each month before my cycle. These breakouts are usually hormone/liver related. So, I started using Zendocrine daily and it completely cleared up those annoying monthly breakouts! This has worked for so many others that I’ve shared this tip with!
4. Diffuse essential oils each day, such as lavender, lemon, balance, ylang ylang, etc. to reduce your stress and relax the body. Your sense of smell is directly connected to your emotional brain, so diffusing oils can immediately change how you feel and reduce stress. Stress puts strain on the adrenals, liver and pancreas and causes an imbalance in blood sugar levels (yes, this can happen even if you don’t eat sugar), so using oils each day to reduce cortisol levels will give your liver the support it needs to be able to work more efficiently.
5. Make sure you are eating enough carbohydrates. While a low-carb diet is all the rage right now, going too low carb can inhibit the conversion of fT4 to fT3 in the liver.
A minimum of 100g of carbohydrates a day from foods such as properly prepared legumes, lentils, potatoes and other starchy vegetables is a good place to start. And, if you’ve been on a very low-carb or grain-free diet for more than 12 months, I would consider talking to your practitioner about adding back some properly prepared gluten-free grains or fermented sourdough.
6. Eat two Brazil nuts a day. Brazil nuts contain selenium and this nutrient helps convert fT4 to fT3. I like to purchase raw Brazil nuts, soak them (to remove the phytic acid) and then dehydrate them in the oven. Check out my Instagram Story I did on this topic.
7. Take steps to reduce your cortisol and overall stress. Read my 17 Steps to Reduce Cortisol Naturally and see what steps you can add to your daily regimen. As mentioned above, when the adrenals are producing too much cortisol this can raise reverse T3 and lower free T3. It can also put a strain on the liver making it more difficult to convert free T4 to free T3.
8. Prioritize adequate quality sleep.
Research confirms that poor quantity and quality sleep is associated with Nonalcoholic Fatty Liver Disease (NFLD). and too little sleep, or poor sleep can increase cortisol levels during the day. Both of these things can decrease thyroid hormone conversion.
If you’re struggling with insomnia, here are my top tips.
9. Drink 1/4 a cup of beet kvass first thing in the morning, at least 10 minutes away from food. Beet Kvass is a tonic that helps decongest the liver.
10. Let go of anger and resentment and practice forgiveness. Negative emotions, most notably anger, can cause a significant burden to the liver which can reduce ft4 to fT3 conversion. In ancient medicine, certain emotions can correspond to particular organs. And imbalances in these emotions can lead to illnesses. A good book to read on this topic is, The Body Keeps the Score.
One research study identified specific patterns between emotions and corresponding bodily organ systems. It found that the liver was indeed closely tied to anger.
In this way, practicing forgiveness and releasing anger can do wonders for liver health. I suggest you talk to a counselor or therapist, someone you trust at your local church, or a friend that will help you walk through this process.
11. Consume foods rich in Vitamin A (aka retinol) daily. Vitamin A is actually essential for proper detoxification. It’s important to remember that Vitamin A is found only in animal foods. Your richest sources are liver (beef, lamb, duck, chicken), cod liver oil, butter, egg yolks, raw cream and cultured raw sour cream.
There is a HUGE misconception out there that vegetables, especially carrots and squashes, are excellent sources of vitamin A. This is absolutely false. Vegetables are wonderful sources of beta-carotene. But beta-carotene is only useful to humans as it is broken down and converted in the body to vitamin A by the body’s vitamin A stores.
This presents a tremendous challenge and serious health problem for vegans. This also explains why most long-term vegans eventually present with disorders linked to liver congestion and why it is not uncommon to see jaundice in vegans. While most vegans have good intentions, they may not have been properly educated as to the significant role vitamin A plays in detoxification as well as in skeletal formation and thyroid function.
12. Avoid intermittent fasting. While this is all the rage right now, most who are struggling with thyroid issues, need to avoid intermittent fasting because it puts too much strain on the adrenals and liver. Here’s more info on this topic.
Have you found other steps that have helped you increase your conversion of thyroid hormone? If so, please share in the comments below!
How can I learn more about the steps I can take for thyroid disease?
I have four fantastic options for you!
- To download my 50 of my top tips to support the thyroid naturally, tap here. I’ll also send you an educational email every few days to help you learn how to support your body naturally.
- If you’d like to learn from first steps you can take to help support your thyroid, check out my class, “5 Keys to Thyroid Hormone Balance”. It’s just 45 minutes and I promise you’ll learn something new!
- If you’re looking for a step-by-step plan for Hashimoto’s that truly works (no more piecing together info!), check out my 90-Day Thyroid Reset Program.
- Book a consult with me for one-on-one help. Here’s info about what working with me looks like.
Hi Carrie –
Thanks, as always, for your wonderful posts.
Would you give us very practical ways to use essential oils on the body, without them getting on clothes, being messy, and feeling like oil is getting everywhere?
Thanks!
Amy G.
I never feel this way when I apply essential oils and I use them daily! I will either add drops to my lotion or I’ll use EO drops with fractionated coconut oil. I especially like combining Frankincense with Copaiba and FCO.
If you’re using pure oils, then they shouldn’t be oily. If they are, that’s a sign that the company cut the oils with something like olive oil, vegetable oil, etc. This is pretty common for store-bought oils. If you haven’t given doTERRA oils a try, I highly recommend them. They soak in almost immediately. I will say there are a few oils like myrrh and vetiver that are a bit more viscous, so they soak in at a slower rate, but they aren’t oily on the skin.
Thanks!
I have made several roller balls with carrier oil and essential oils in them. I guess I should find some skin that is exposed since I don’t like the feeling of getting the oil on my clothes. Maybe the FCO is the oily part. I haven’t tried doTERRA yet but do purchase top brands. Thanks again!
Amy
This is wonderful information on the thyroid and the liver as well as the adrenals. Thank you so much.
However, eating beans, legumes, starches and gluten free grains makes my nerves in my hands, arms, and feet tingle and go numb. What might be going on?
My fingers go numb also when using, holding, and touching my phone screen. What might that be caused from?
I am tired all the time. No energy. I struggle to do the basics of daily living. Any ideas of what this might be?
I’m not sure what might be causing that, but if you notice a negative affect after you eat those foods, then it might be test to avoid them for now.
You might have a nickle allergy. Or some other type of allergy. Those foods are high in nickle.
I have a similar reaction to those things but it’s more on the side of non epileptic seizures. I think I have leaky gut and a damaged blood brain barrier that triggers inflammation on a nerve. Something to look into. But also maybe it’s causing inflammation on a specific nerve for you because maybe you need a chiropractic adjustment from someone who does cranial sacral and muscle testing to do adjustments. Some things I can have after they are completely fermented so that might be a way to be able to eat those things, but for some things it doesn’t seem to be enough. I thought it was interesting though to read here that the thyroid issues can cause food sensitivities. I will have to look further into this. My thyroid looks like a bone now and is so painful, maybe if I put more focus into healing that some things will get better with my seizures too!
I know this is quite old so i’m not sure if you’ll see this. I too am dealing with the numb and tingling issue in the same way you described. I am narrowing mine down to very low electrolytes as well very low B12. Hashimotos itself can also cause the numb and tingling sensation as well. I started getting B12 injections weekly which have made quite a bit of a difference along with a ten week magnesium infusion, along with several other minerals, once weekly for the ten weeks, this is after the magnesium challenge I did with my Functional Medicine Doctor. Sorry you are dealing with this as well, I hope you’ve healed since it’s been 6 plus years since your post.
How much cod liver oil do you think is enough to support the liver? The bottle serving size recommendation?
is there an easy way to print this article? thanks!
I don’t have a software on my site that enables printing of articles. You can copy and paste it into a document and then print!
Thank you for easy tips and information! I was vegetarian for 40 years and Vegan for 10 of those years…I believed I was eating the perfect diet for me until 5 years ago when I began manifesting thyroid nodules, thinning hair and eyebrows, brittle nails and joint issues…….I’ve since integrated wild caught salmon, grassfed beef, collagen and bone broth, coconut oil etc. and the healing has been miraculous!
Any chance you could give me more details on your diet? I have a supersensitive thyroid and nodules and I would like to find a way to slow the process or even reverse it if possible. Thank u so much
Castor oil packs and iodine are incredibly helpful for nodules and for recipes, check out my cookbook, “The Grain-Free Family Table” or the hundreds of gf recipes I have here on my site!
Here are the links:
Castor Oil Packs: https://deliciouslyorganic.net/castor-oil-packs-detox/
Why iodine is needed for the thyroid: https://deliciouslyorganic.net/iodine-hashimotos-thyroid-disease/
Cookbook: https://amzn.to/2wkyHqi
Recipes: https://deliciouslyorganic.net/category/index-categories/grain-free-2/
How does the casteroil pack work from the outside? I am skeptical can you convince me?
I am also curious about how you do a casteroil pack. Can you explain?
If you click on the word “castor oil pack” in the article it will take you to an article explaining how to do them.
How many of these things are good to do together? And how do we know where to rub the Zendocrine? I only have one lob of my thyroid so I try to take the best care of myself. I normally like fasting since it just fits for me mentally but I do horrible on it. I do not feel well and I gain weight so fast. Thanks for all of this info!
You could do all of them together, but if you’re just starting out, I would take baby steps and integrate one new step each week or every other week so that you don’t put too much strain on the liver. You can either rub the Zendocrine over the liver, or place a drop under the tongue each day. I know using essential oils is controversial, so if that isn’t something you want to do, just do what you are most comfortable with.
Thanks as always! And such a timely topic for me!! I’ve experienced severely heavy cycles the past few months and have crossed the bridge to anemia and I KNOW it is liver/adrenal related. I have slacked from using my thyroid EO blend before bed, and have also slacked from using LLV and zendocrine daily. Your wisdom is always welcome.
I’m glad this was a good reminder for you and that you’ve found the oils to be helpful for you. 🙂
What is your thyroid EO blend? Thanks for sharing!
It depends on exactly what your goals are. I highly recommend taking the free class where we go over everything in detail, but for a general blend, go here: https://deliciouslyorganic.net/essential-oils-for-thyroid-support/
Thank you for this fantastic resource! I saw there are also Zendocrine softgels available. I have never applied nor ingested essential oils.. I’m wondering what your thoughts are on softgels vs. topical/sublingual application as you mentioned above? Many thanks!
I prefer the Zendocrine oil (not soft gels) because the essential oil blend doesn’t contain any preservatives. To learn more how to use them, I highly recommend my free online class. It’s packed with helpful info! https://app.webinarjam.net/register/21771/01e0c62bff
Fantastic! Thank you!!
Hi Carrie! I have Hashimoto’s with some nodules but with lifestyle improvements I am steadily getting better. I’m also currently 12 weeks pregnant! Which of these steps are safe to do during pregnancy because I’m finding out not everything I used to do is recommended while pregnant. For example i’ve had to lower my Vitamin A intake and don’t do castor oil packs anymore. I take warm lemon water in the mornings, but if beet kvass is better i’ll just switch to that. Despite all of my questions I’m so excited to be having a baby!
Congrats on your pregnancy! For pregnancy, we recommend to our clients that at a minimum they consume a nutrient-dense diet that is free from as much sugar and processed foods as possible, that all grains, seeds, nuts and legumes are properly prepared and to eat plenty of animal fats and organ meats for the fat soluble vitamins A, D, E and K. Because I don’t know your full health history, I can’t say for sure exactly what your body needs. But, a nutrient-dense diet, using pure essential oils to keep your stress levels as low as possible, and epsom salt baths is a good start. If you’d like to book a 30-minute Nutritional consult with me, feel free to give our office, Biodynamic Wellness, a call! 858.259.6000
Why should you not do a castor oil pack if you have an IUD? I have one to stop my periods, not for birth control.
It could possibly cause it to dislodge, and/or excrete excess copper into the system.
I have had a thyroid ablation. How do you suggest to help the tyroid when part of it has been destroyed. I would prefer not to take synthroid the rest of my life.
Thanks
It’s hard to give advice for this without knowing your full health history. If you’d like to book a consult with me, you can call our office, Biodynamic Wellness, at 858.259.6000
I had my thyroid removed due to thyroid ca 9 years ago. My endo says my levels are normal based on labs however i struggle with weight loss and am chronically cold. Despite eating a Whole Foods diet and regular exercise 6 days/week, Would your thyroid suggestions help me as well?
Did your doctor just look at TSH, or did they also look at T4, T3, FT3, etc.? It could be that your TSH is “normal”, but that you’re under converting thyroid hormones, so the proper amount of T3 isn’t getting to the cells which can result in being chronically cold. Or, it could be that cortisol levels are too high which is creating high FT3 levels and weight gain. I’d read this post, and start taking some of the steps listed:https://deliciouslyorganic.net/20-steps-heal-adrenal-fatigue/
Hi – is it okay to do a castor oil pack even if your TSH, T3 and T4 are all normal?
(I can’t remember the difference between the FT3 and T3, etc, but the numbers are all good – this coming from a naturopathic doctor.)
The only issue I’m having lately is some weird thing on my face. It started with my chin, then moved to my cheeks (near my nose) and now my nose. The best way to describe it is like having been in the ocean and having the salt and/or sand sticking to wet skin. I’m 56 and don’t mind getting older. I just don’t want to LOOK older with dried-out skin. I use the OCM and have been moisturizing with shea butter and coconut oil. When I fell on this article it gave me hope, but when I re-read all my numbers I began to wonder if I should bother with the pack.
Yes, the castor oil packs will benefit you even if your levels are normal. It’s actually a great habit to get into to help support the liver. Usually skin issues like that are tied to liver congestion, so I’d give the castor oil packs a try and see if it helps clear things up.
Any advice for healing my goiter with supplement
Iodine supplementation along with castor oil packs over the thyroid can be incredibly helpful. If you’d like, you can call our office, Biodynamic Wellness, and book a consult with me (I work with all clients long-distance) to help you walk through the process. Here’s the number: 858.259.6000
Hi, Carrie –
I’m trying to get your specific instructions for soaking and dehydrating brail nuts, but when I click on the link it just takes me to your general instagram page and I can’t seem to find your past stories. Am I missing something?
I appreciate the help!
If you go to my profile page on IG, then you’ll see little circle with titles. You can scroll through those and find the one you want to watch.
Hi Carrie! Thank you for sharing your immense knowledge regarding thyroid solution. I am very grateful to you. I’m using Himalayan salt in cooking. I had thyroid problem before. After using it in my cooking, my thyroid problem has improved.
Cheers!
Hey, I’d love to call and book with you. I have your fist book and have been following you for years. One thing I will say though is that intermittent fasting has really helped me but I could never do it without my adrenal cocktail that I learned from Morely Robbins The Root Cause Protocol. That has been revolutionary to my life! Because of my auto immune disease I waste electrolytes but when I keep them topped off I can fast and that has really helped my healing and I have lost 18lbs. I have only gained weight for 9 yrs due to illness no matter what I did. I agree w you it can be super traumatizing to some people with thyroid/adrenal issues especially if they waste precious electrolytes like I constantly do! Anyway, looking forward to working with you! You are awesome!
Suzanne, I know you posted this in 2018, but wanted to see if you are still doing the Adrenal Cocktail? Thanks!
Why must you people always talk crap about veganism?
You do realize meat and dairy literally kill people daily, right?
This article completely lost all credit after that bs.
It’s a fact that Vitamin A (aka: retinol) is only in animal foods. This is not a statement against anyone. I agree that conventional meat and processed/conventional dairy are very harmful for the body, but pastured meats and cultured/raw dairy are very healthy food for the body.
It’s a fact that they thyroid needs vitamin A to function properly, and yes, the body can convert a small amount of beta carotene to retinol, but this conversion cannot happen properly if one has thyroid, gut, liver or immune system issues. So, when one has thyroid disease, it’s imperative to consume Vitamin A rich foods.
Stating nutritional facts doesn’t discredit anyone. If you have studies that prove that retinol is in plants, or that even with thyroid disease, gut dysbiosis, or liver congestion the body can convert plenty of beta carotene to retinol to keep the body functioning at it’s optimum level, please send them over. I’m always eager to learn!
Just stumbled across this and a few other articles of yours. Everything you said helped me tie up alot of loose ends. Esp the liver info and the intermediate fasting. I’m a Muslim and haven’t been able to participate this year in Ramadan. Kept getting really sick each day. Finally gave up the fasting decided my body just was telling me no. This gave me the confirmation. I’ve been struggling to get this flair up calmed down its the worst one I’ve ever had. Looking forward to more information from you. I have some hope again.
I’m so glad you found the information helpful and that it brought you hope. 🙂
Would it be just as effective to make a roller ball with FCO and Zendocrine oil instead of rubbing a drop over your liver each time? If so, how many drops of Zendocrine would you recommend for a 10 ml roller ball?
If it’s diluted, you’ll apply less oil over the liver with each application, but if you feel more comfortable using a diluted oil, than that is fine. I would do 20 drops of Zendocrine in a 10ml roller ball and top off with Fractionated coconut oil.
I need info on a healthy thyroid function to convert T4 to T3 effectively to help my husbands IPF ?
This article addresses 12 ways to improve thyroid hormone conversion.
For low T3 many say selenium and iodine. Eggs contain plenty of both. Maybe the easiest solution?
While there are often deficiencies when someone has thyroid disease, a conversion issue is often rooted in liver congestion so just adding some selenium or iodine usually won’t fix the issue.
I’ve been diagnosed Hypo with Graves antibodies. I’ve gotten quite a few of my antibodies down & My Reverse T3 has finally normalized, with a anti-inflammatory, gluten, dairy, grain free diet and supplements but my FT4 (1.06 Ref 0.82-1.77) to FT3 ( 2.3 ref 2.0-4.4) is still not converting and my TSH shot up to 15! and my doc wants to put me on Cytomel and Tirosint. I’m petrified of the side effects Carrie. Please help.
I’ve been drinking your homeade Kvass for the last 4 months, doing castor oil packs at least 5 nights a week and rubbing my own homemade zendocrine essential oil over my liver twice daily. ( Plant Therapy)
I’m sorry you are struggling. I recommend taking my online thyroid course and following the protocol. It will walk you through everything step-by-step! 🙂 https://deliciouslyorganic.net/thyroid-online-course/
hi. In your article about reversing Hashimotos you mention going grain-free. But here in #5 you mentioning add grains in. What would be your recommendation?
My wife is currently taking Armour Thyroid daily and Promline Iodine (every 3rd day). We find your articles very helpful and she is doing most of it. She will try the castor oil pack soon. She eats mostly organic fruits and veggies, grass fed meats and eggs, and very limited processed foods or sugar. we were trying to fast, so glad we found your articles to stop us from dong that.
If one has antibodies, then, in general, I recommend staying off grains until the antibodies are back to normal ranges, or they have improved significantly and all gut and digestive symptoms have cleared. Of course, one should always consult with their practitioner as to the best course of action.
Hi Carrie- I’ve been following you for a good while now. Thanks for all of your great info!
I’ve done all of the things you recommend to help my T4 convert to T3 and nothing seems to help. I have Hashimotos and I eat a really clean diet ( was on AIP first and now a personalized paleo) Most of my antibodies have come way down but my Free T’s aren’t budging. Sometimes my TSH is as high as 12 but I don’t feel terrible. 🤷♀️ I eat Organic and pasture-raised/grass-fed. No processed foods or sugar. Plus I do yoga meditation and walking. I did have to stop drinking the kvass because I discovered a histamine intolerance and I’m working on that now. But I do a castor oil pack just about every night.
Is there a liver detox that you recommend for congestion?
The tips I give in this article are the ones I recommend starting with. When it comes to more in depth info about lowering TSH, balancing fT3, and liver detox, I recommend checking out my thyroid course and protocol. I walk through all of this step-by-step! https://deliciouslyorganic.net/thyroid-online-course/
.how do I make the kvass drink please
Here you go! https://deliciouslyorganic.net/how-to-make-beet-kvass/