Healthy Hormones

How to Increase T3 Levels Without Medication

If you have a thyroid issue and want to feel better, then increasing your T3 level to the optimal range is the single most important thing that you can do.


Because T3 is the active thyroid hormone.

Most people have lower than optimal free T3 levels even if they are taking thyroid hormone medication.

So how do you increase your T3 level?  That is the critical question.  

I will try to give you all of the tools you need in this article to start increasing your T3 level and get you feeling your best.  Some are simple and straightforward while others are more difficult.

Here we go...


What Is T3?

Let's start with a quick tutorial about the thyroid which will help you understand some of the terms I will be using and what they mean.

The thyroid gland is a factory.  It's job in the body is to make thyroid hormone.

The thyroid depends on the pituitary gland in the brain to tell it how much thyroid hormone to produce. The pituitary does this by secreting Thyroid Stimulating Hormone (TSH).

The majority of hormone that the thyroid makes is T4.  T4 is inactive and is basically the transport form of thyroid.  It serves as a reservoir that the body can draw from when it needs more T3.

A small amount of T3 is also made directly by the thyroid, but most of it is produced outside of the thyroid gland by converting T4 to T3.  This is done by an enzyme called a deiodinase.  

T4 can also be converted into Reverse T3.  Reverse T3 is the anti-thyroid hormone.  It will bind to thyroid receptors in the cells but does not trigger any function.  It therefore effectively blocks that thyroid receptor.

Too much reverse T3 can result in a substantial reduction of thyroid function in the body.  Therefore in most cases it is best to have as low of a reverse T3 level as possible (<15).  Click here to read more about reverse T3.

Most T3 in the blood is bound to a protein.  When T3 is bound, it is unable to attach to the thyroid receptors in the cells.

A very small percentage of the total amount of T3 in the body is not attached to a protein.  We call that the free T3 level. Since it is not attached to a protein, it is free to attach to the thyroid receptors in the cells and trigger the functions that it is designed to trigger.

Therefore, the free T3 level is actually a measurement of how much active thyroid hormone is present in the body.

In my practice, I like for the free T3 level to be >3.5 if possible.

How To Increase T3 Levels

As you can tell from this illustration, there are 4 main areas that should be optimized in order to maximize your T3 level:

  • T4 hormone production
  • T4 to T3 conversion
  • T4 to reverse T3 conversion
  • Cellular sensitivity to T3

Addressing all 4 of these areas will increase your chances of getting your T3 level optimized.

Let's break these areas down further, plus I will discuss some other things that you can also do to get your thyroid working at optimal efficiency:

1.  Maximize Thyroid Production

There are over 15 nutrients that are necessary for normal thyroid hormone production.

Most of them are usually found in adequate amounts in the Standard American Diet.  However, it is common to be deficient in some of them.

Iron and iodine are two of the nutrients that are necessary to maximize thyroid production and it is common for people to be deficient in them.

- Optimize Iron

Iron is completely intertwined with the thyroid.

If the iron level is low, thyroid medication doesn't work as well, and conversion of T4 to T3 is reduced.

Conversely, thyroid hormone is needed to properly absorb iron.  

So when thyroid levels are low it leads to iron deficiency which in turn worsens thyroid function, creating a vicious cycle.

Iron is also required for proper adrenal function.  When the adrenals aren't working it puts an increased strain on the thyroid which can lead to adrenal fatigue and other issues.

To find out if you are low in iron, you can ask your doctor to order a CBC, serum iron, TIBC, and ferritin level.  If you are low, then treatment with a supplement may be necessary.

As a general rule, thyroid patients tolerate liquid iron better than pills.  It causes less constipation and is usually better absorbed.

If the liquid iron is not adequate to raise the iron levels, it may still be necessary to switch to an oral tablet such as this one.

Remember, low iron is often due to a deficiency in your diet, but it could also be a sign of blood loss.  If your iron is low (especially if you are anemic), you need to see your doctor about it.  You could have gastritis, a stomach ulcer, or some type of lesion in your small intestine or colon that is causing the blood loss. It could be life-saving to have this investigated.

- Consider Iodine

Iodine is a tricky subject when it comes to the thyroid, especially if you have Hashimoto's Thyroiditis.

Many experts are adamant about the importance of iodine while others are afraid to use it.

The fact is, iodine is required for thyroid hormone production.  Adequate amounts of iodine are necessary if you want to have optimal thyroid function.

So if you decide to use it, I would use this as a guideline:

  • Start low and go slow
  • If you have Hashimoto's and want to try iodine, make sure you are also supplementing with selenium.  Studies suggest that iodine can increase thyroid antibody levels if you are deficient in selenium.

Start with 325mcg of iodine per day and continue that for 10-14 days.  You can then increase the dose by 325mcg daily every week as long as you are noticing improvement.

If you notice worsening symptoms then stop it immediately.

Click here for the supplement that I recommend.

Make sure that you monitor your thyroid antibody levels if you have Hashimoto's.

2.  Improve T4 to T3 Conversion

Efficient T4 to T3 conversion is critical for normal thyroid function.

Most conventional doctors are taught to only check the TSH and occasionally the T4 level when monitoring thyroid function.

This assumes that the T4 to T3 conversion process is working normally.  However, in my experience, that just isn't the case.

Chronic inflammation in the body (arthritis, diabetes, obesity, etc.) impairs the conversion process.  So does some nutrient deficiencies.

That may be why you are still having typical symptoms of hypothyroidism even though your TSH and T4 levels are in the normal range.

The following list is far from complete, but it includes what I have found to be the most common reasons why T4 to T3 conversion is impaired.  Click on each nutrient for my preferred brand.

Inadequate zinc levels typically results in more T4 to reverse T3 conversion and result in worsening thyroid function.  Zinc is also a powerful anti-inflammatory and helps regulate your immune system.  It also is good for your skin.

Selenium is also essential for normal T4 to T3 conversion.  It also helps to regulate the immune system and can help reduce thyroid antibody levels if you have Hashimoto's.   I typically recommend taking 200-400mcg daily. Click here to read more.

- Reduce T4 to Reverse T3 Conversion

Even though I will discuss this is more detail later, it should be listed  here as well.  

Reducing the T4 to reverse T3 conversion will mean that the T4 is being channeled into converting into T3 instead.

3.  Improve Your Gut Health

This may surprise you, but up to 20% of the T4 to T3 conversion occurs in the gut!

The amounts and types of gut bacteria play a huge role in thyroid function.

With that in mind, this shouldn't surprise you:  Most thyroid patients have at least some level of gut issues.

Why?  Because when the thyroid is low it makes your intestines move slower which can lead to constipation.  It can also increase your risk of developing SIBO (small intestinal bacterial overgrowth), yeast overgrowth, and acid reflux (GERD).

Low thyroid also causes less stomach acid to be produced which further reduces the absorption of nutrients.

All of this also predisposes you to develop increased intestinal permeability, better known as leaky gut syndrome.

A leaky gut then allows foreign proteins to enter the bloodstream.  One such protein is called LPS.

LPS has been shown in studies to lower T3 levels in the blood.

Have I convinced you how important gut health is to thyroid function?

So what can you do to improve your gut function?  

The first step is to make a proper diagnosis.  That can usually be done with a thorough history.

- Betaine with Pepsin

Pharmaceutical companies want us to think that almost all of us produce too much stomach acid.

If you are having heartburn after eating dinner, it's because you have too much acid, right?

Wrong!  The problem is not too much acid, instead the acid is going to the wrong places (your lower esophagus instead of staying in your stomach).

In reality, many people don't produce ENOUGH stomach acid, also called hypochlorhydria.  

Studies show that up to 40% of people over age 40 have hypochlorhydria.  By the time you reach 60 years of age that number goes to over 50%!  In fact, up to 30% of people over 60 have achlorhydria, which means they don't produce stomach acid at all.

So take that information and just imagine how much worse those numbers get when you add proton pump inhibitors, H2 blockers, and antacids that so many people take on a daily basis.

Remember, stomach acid is critical for 3 primary functions:

  • Acid in the stomach causes the breakdown and digestion of food which allows nutrients to be extracted and absorbed into the body.
  • An acidic stomach serves as a barrier against bacteria, yeast, and other organisms that grow normally in the intestines.  Without adequate stomach acid, these organisms will colonize the stomach and create all sorts of problems including gastritis and ulcers.  H. pylori is an example.
  • The acidity of the stomach is what triggers the pancreas to release digestive enzymes which further break down the food we eat so that nutrients can be extracted from it.

If you want to read more about this subject in detail, I highly recommend the book "Why Stomach Acid Is Good For You" by Dr. Jonathan Wright.

Okay, so what can you do about this?

I would suggest a trial of Betaine Hcl with Pepsin.  

Betaine is actually a capsule containing a small amount of hydrochloric acid.  Pepsin is a digestive enzyme.

Start by taking 1 capsule at the beginning of each meal.  If you are tolerating it without side effects, then after a few days increase your dose to 2 with each meal.  You can continue to add a capsule every few days until you begin noticing a mild burning in your stomach.  When that occurs, decrease your dose by 1 capsule from what you were taking when the symptoms occurred.

In my experience, most people need 1-3 capsules per meal.  However, if you have a long history of PPI, H2 blocker or antacid use, you may need more.

Get my preferred brand here.

If you are currently taking a PPI, H2 blocker, or antacid on a regular basis, I would suggest trying to wean off of those before trying the Betaine.

If you are on a PPI such as Nexium or Prilosec, try converting to an H2 blocker such as Zantac or Pepcid. It will be easier to wean off of those medications than it will be a PPI.

Also, if you currently have an active stomach ulcer, I would not recommend a trial of Betaine until after the ulcer has completely healed.

- Digestive Enzymes

Digestive enzymes help to break down food which allows your body to extract the vital nutrients in the food.

They also help break down immune complexes in the blood which helps treat autoimmune conditions.

Click here for my preferred brand.

- Probiotics

High potency, multi-strain, multi-species probiotics cah greatly reduce local inflammation in the gut as well as reduce systemic inflammation.  I always recommend a probiotic to all patients with hypothyroidism (especially Hashimoto's) for at least 2-3 months.

It is somewhat controversial whether you should take probiotics on a daily basis.  Many experts feel that is unnecessary.

I usually break it down to whether the patient has any gut issues or not.  If they do, they should take a daily probiotic.  If they don't they can probably used them only during times of sickness or severe stress.

Click here for my preferred brand.

- Other Gut Imbalances

If after reading this you believe you may have other gut imbalances such as SIBO, SIFO (small intestinal fungal overgrowth), or leaky gut, those issues will need to be addressed if you want to optimize your T3 level.

That will require sitting down with a doctor that is familiar and comfortable with those conditions.

4.  Lower Your Reverse T3

Reverse T3 and T3 are inversely proportional to each other.  As one rises, the other will fall and vice-versa.

That is because they both are produced from T4. 

So reducing your reverse T3 production will mean that more T4 is being converted into T3.

So how do you do it?

Think of the reverse T3 level as indirect marker of inflammation in the body.  Any inflammation will typically cause the reverse T3 level to rise.

Therefore, most of the things I list below address various forms of inflammation.

- Reverse Insulin Resistance and Leptin Resistance

High levels of insulin and leptin tell your body to create MORE reverse T3. 

It will be very difficult to lower your reverse T3 levels unless you address these issues.

Click here to read more about how to treat insulin resistance and click here to read more about how to treat leptin resistance.

- High Intensity Interval Training (HIIT)

Adding HIIT exercise to your regular routine will create a demand for more thyroid hormone in your body.

In effect, it will push your T4 conversion more down the T3 pathway and reduce your reverse T3.

- Stop Restricting Your Calories

Calorie-restricted diets will put your body into "starvation mode."  When that happens, T3 production is rapidly reduced and reverse T3 levels soar.  

This is one of the ways that excessive calorie restriction damages your metabolism.  Click here to read more.

- Reduce Inflammation

Besides insulin resistance and leptin resistance, there are other sources of chronic inflammation that will result in an elevated reverse T3 level.

These can include other autoimmune conditions, environmental toxins, and even obesity itself.

It is critical to get a thorough history and physical exam including blood work to identify all possible sources of inflammation in your body so that each be addressed directly.

There are some blood tests that you can request from your doctor that are nonspecific markers of inflammation in your body.  

The most common tests are the erythrocyte sedimentation rate (ESR) and the c-reactive protein (CRP).  If either is above the reference range, it is a sign that there is unidentified inflammation in your body that should be addressed.

- Take a T3 Medication

I know.  The title says "without medication."  However, this needs a quick mention.

If you are taking a T4 only medication such as Synthroid or levothyroxine and your T4 to T3 conversion is impaired, you are only "feeding the monster."  You are just supplying T4 which will make more reverse T3 instead of T3.

The quickest way of lowering the reverse T3 level and raising the T3 level is to take a T3 only medication.

This bypasses the conversion process altogether.  Your need for T4 will decrease which will also result in a dramatic decrease in reverse T3.

This can be added to the T4 only medication or can replace it altogether.

You can get some benefit by switching from a T4 only medication to a natural dessicated thyroid (NDT) medication such as Armour, NP thyroid, or Nature-throid.  However, it may still have too much T4 in it to significantly reduce the reverse T3 and increase the T3.

5.  Manage Stress and Optimize Your Adrenal Function

The adrenal glands and the thyroid gland are closely linked.

As cortisol levels increase, so does the TSH, which makes the thyroid function worse.

Also, as thyroid function decreases, this puts even more stress on the adrenals to make up the difference.

Eventually, the system can no longer keep up and adrenal fatigue results.

In my experience, literally ALL hypothyroid patients have some degree of adrenal fatigue.

That is why I recommend that most hypothyroid patients take an adrenal supplement.

For the sake of this article, I would suggest a few basic things to help manage adrenal issue:

  • Take an adrenal adaptogen - Essentially all patients would benefit from these herbs that help balance the adrenal function.
  • Take an adrenal glandular - Use this if you are having severe stress or severe fatigue.  Typically only needed for 3-6 months.  Avoid if you have an allergy to it.
  • Cut out caffeine - Caffeine may give you a temporary boost, but it also adds additional stress to your adrenals and will ultimately make your symptoms worse.
  • Start doing regular meditation and/or yoga - This will drop cortisol levels and let your adrenals rest.

If you feel you need to learn more about this, click here for my article on adrenal fatigue.

6.   Optimize Your Liver Function

Up to 60% of thyroid conversion occurs in the liver.

Obviously, making sure your liver is healthy and functioning well is critical if you want your T3 levels optimized.

Your liver can be assessed by having your liver function tests monitored.  The primary test are AST and ALT.

If either test is >20, it is a sign that you have some liver impairment.

By far, the most common cause of liver impairment is insulin resistance.  The insulin resistance can result in excessive fat deposits in the liver resulting in a fatty liver.

Reducing any liver dysfunction may result in the single greatest increase in your T3 level of any therapy that we have discussed.

7.  Improve Your Diet and Lifestyle

The foundation of any successful health plan always includes 5 things:

  • Healthy diet
  • Activity level/exercise
  • Stress management
  • Good sleep hygiene

If that foundation isn't established, all of the supplements, medications, and other therapies will fail miserably.

I realize that this is easier said than done, but it is critical if you want to feel your best.

In the case of this article, you must be eating healthy, exercising, sleeping well, and managing your stress in order to maximize your T3 production.

If you need a simple place to start, consider the Whole 30 Diet or the Ketogenic diet.  

If you are having trouble with those or if you feel you need more instruction, I would recommend hiring a nutritionist for some one-on-one instruction.  You are worth it!

I would also recommend hiring a personal trainer that will give you a personalized exercise program that will be safe and effective.


Raising the T3 level is easy for some people and hard for others.

The key to success is identifying WHY yours is low and addressing the root causes.

These can include poor diet, lack of exercise, nutrient deficiencies, and excess stress.

There could also be unidentified sources of inflammation in your body or your liver and gut might not be working as efficiently as they should be.

Finally, it may also be the situation of needing a different thyroid medication.

Find a doctor that is willing to investigate all of these potential causes and is open to trying different thyroid medication.

Now it's your turn...

What have you tried to increase your T3 levels?

What has worked and what hasn't?

Leave any questions or comments below.

About the Author Dr. Jeff Whelchel

Dr. Whelchel is a family physician who specializes in functional medicine, especially hormone optimization. He has over 20 years experience in private practice managing patients with various medical issues. His passion is helping patients reach their full potential of wellness and quality of life. He grew up in the Texas Panhandle where he currently lives. He is married and has 3 awesome children.

Leave a Comment:

Diane Redden says January 20, 2020

Finally an explanation that can be understood!

    Dr. Jeff Whelchel says February 10, 2020

    Thank you Diane. I hope it helped.

Kim Night says January 31, 2020

I am taking the time to comment on this article. I have studied a Homeopathy and functional medicine for 20 years. Congratulations, you did the best job explaining this in a concise and spot on helpful manner. I wish I could get this to the millions who suffer needlessly I am taking the time to comment on this article. I have studied a Homeopathy and functional medicine for 20 years. Congratulations, you did the best job explaining this in a concise and spot on helpful manner. I wish I could get this to the millions who suffer needlessly!

    Dr. Jeff Whelchel says February 10, 2020

    Thank you Kim for the nice words. Let’s keep getting the word out!

Hiromi says July 30, 2020

Thank you very much about your post. Especially reverse T3. I did not know reverse T3 is a flip side of a T3. I am going to try to reduce reverse T3.

Lorraine says October 3, 2020

Interesting article.. I have taken T4 meds for 25 years and suspect that I have developed a t4 to t3 conversion issue. I have gained a lot of weight and no matter what i do it will not shift and I still have symptoms despite my TSH being level being very good. No option to add T3 as I live in the uk but hopefully there will be some useful information here to improve my health.

Loria says October 8, 2020

This has been the most comprehensive explanation I’ve read regarding thyroid function and how it all ties into gut health, inflammation, and adrenal glands. My traditional doctor is upset that I see a function medicine doctor.

    Dr. Jeff Whelchel says November 11, 2020

    Thank you for the kinds words. People often feel threatened with information that they don’t know.

Melody says May 20, 2021

Thank you for the great article on how to increase free T3! Can you tell me please what are optimal levels of zinc, selenium, vitamin A, vitamin D, iodine and iron in your opinion? Blood test ranges are so large and every doctor has a different opinion so blood work is so tricky.

Also, I already take and do a lot of what you recommend because I have Crohn’s disease, have had it my entire life since 3 years old (I’m 46). I lost my entire large intestine when I was 21. I treat myself naturally with herbs and supplements and with a very strict low-inflammation diet (basically keto but I do eat organic oats and brown rice occasionally). I do not take any drugs like the biologic drugs or steroids because I did all of that early on and the drugs caused so many other problems and nearly killed me; I do better treating myself naturally.

Anyway, my free T3 was 2.49 the last time I tested which was 6 months ago. My total T4 was 12.3 and my TSH was 1.547. I also had a 24 hour urine cortisol test done and was told my results were, cortisol 5 ug/L and 8 ug/24hr. And I was told that is “normal”.

After reading your article, I am very interested in the adrenal adaptogens and the adrenal glandular because my brain and my body are under constant stress. I have hair loss issues on the sides and front of my head, which is not a new thing but I’ve struggled with it my entire life.

In my case would you say I should try both the adaptogens and the glandular or just one over the other? Also your article said to take the glandular for 3 to 6 months for most people but since my illness and stress is chronic should I take it perhaps indefinitely? What kind of blood tests should I do to check on my adrenals?

I am also interested in trying the Betaine Hcl w/pepsin. I have always been curious about that but have never tried it. In my case would you recommend that I try that too?

Thanks for your help!

    Dr. Jeff Whelchel says May 30, 2021

    Hello. Thanks for you nice compliments.

    The single best test to evaluated adrenal function in my opinion is a Dutch test. You can get them on Amazon, although they are expensive. Serum tests are unreliable, but a morning cortisol test is helpful if it is abnormal. If you are <8 you know you have a problem or if it is >25.

    I believe adaptogens are safe and should be used for most people with thyroid issues. If your cortisol level is low, I also think it is safe to take an adrenal glandular for a few months to get it built back up. I often give patients both at the same time then recheck their cortisol levels in about 3 months.

    Your free T3 is way too low. It could be from inflammation in your body, but that needs to be addressed with your doctor. You would feel so much better if you could get it >3.5.

    As far as normal labs levels of the various nutrients, they are unreliable at best. The only one I am comfortable saying is to keep your 25-OH-vitamin D level in the 50-100 range.

Tamara says July 13, 2023

Wondering why the carnivore diet is not suggested? While Keto diet is more preferred than the standard fare, I suggest that the cravings will never go away until they are cut off. Inviting the body and brain to “get a little fix” can be a recipe for failure. Dr. Whelchel, this way of eating changed my life and same for so many “underground” food patriots. I wonder, are you willing to give it a go for three months? I know it is going to help you, too! Hope to see you sitting around the carnivore table with the most victorious people I’ve ever met.

    Dr. Jeff Whelchel says August 20, 2023

    Hi Tamara. The carnivore diet can be a great option, especially with someone who is suffering from multiple possible food sensitivities or autoimmune issues. It is really the ultimate “elimination diet” if you think about it. I have some long term concerns for using it indefinitely as it can be deficient in some nutrients. It depends a lot on the quality of meats you are consuming. I’m glad you are feeling better!

LINDA PLANTE says January 11, 2024

This is hands down the BEST information I’ve ever seen! Thank you for putting this together for those of us who are having less-than-optimal test results.

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