The Complete Guide on How to Fix Thyroid Function Naturally

The standard approach to poor thyroid function is to test TSH and hand out T4. That misses most of what matters. Your thyroid controls your metabolism, mood, energy and gut health, and it is being ignored by your doctor.

This is the ultimate and complete guide to thyroid health so you can optimize it.

Symptoms of Poor Thyroid Function

The most common symptom of poor thyroid function is being constantly tired, no matter how much you sleep. I have written more about the root causes of constant fatigue and low energy.

But bad thyroid health can manifest in seemingly infinite ways. Here are some of the symptoms documented by Broda Barnes, MD:

Anxiety and Depression

Anxiety and depression can be caused by hypothyroidism.

• Low T3 and T4 are often seen in both conditions
• Proper thyroid hormone treatment can alleviate these

The brain needs lots of energy. When it lacks it, things go haywire.

Mental and metabolic health are synonymous.

Gut Issues and SIBO

Gut issues are often caused by a lack of thyroid hormone.

Bacterial overgrowth (SIBO) is common in hypothyroidism, as having poor thyroid function:

• Lowers enzyme secretion
• Fosters pathogenic bacterial growth (impaired immunity and metabolism)

I have written more about a root-cause approach to SIBO and gut dysbiosis.

Low Testosterone

Hypothyroidism causes low testosterone. Thyroid supplementation nearly doubles it in clinical trials.

Hypothyroidism impairs:

• Testosterone production
• Sperm motility and quality

This is likely due to high prolactin, decreasing steroid output in the testes. Treatment can resolve these issues. I have covered more in my guide to increasing testosterone naturally.

I could go on about the signs and symptoms. But if you have any health issue that you can't really seem to put your finger on or explain, you should consider the thyroid as a prime cause.

How Thyroid Hormone Production Works

Thyroid hormone production starts in the brain, which produces thyrotropin releasing hormone (TRH).

TRH goes to the pituitary gland, producing thyroid stimulating hormone (TSH).

TSH then stimulates the thyroid gland to produce T4, and a little bit of T3.

T4 acts to suppress the release of TSH from the pituitary, to keep things balanced.

T4 is an inactive precursor hormone. It needs to be converted into T3 to truly be active.

T3 is produced from T4 in other tissues, mainly the liver.

Why Standard Thyroid Treatment and TSH Testing Fall Short

The problem is that the standard treatment for poor thyroid function is to give people T4. If you have problems converting T4 into T3, this will actually make the problem worse.

Doctors also typically only test for TSH. A low TSH signals high thyroid hormone production.

The issue here is that, again, this does not tell you if you have enough T3, which is the important part.

TSH can also be suppressed by other things like stress, so it can actually be very misleading.

Testing for Thyroid Function: Beyond TSH

In addition to the standard TSH, you can also test for the free and total levels of T3 and T4.

These measures are helpful, but still not necessarily all encompassing.

The hormones do not need to be "free" from their carrier proteins in order to exert their effects.

Thyroid hormones also need to bind to receptors within the cell in order to activate metabolism, and this binding can be inhibited, too.

Blood tests are not capable of measuring these processes.

Reverse T3

Another test for thyroid function is reverse T3.

T4 can be converted into either T3, the active thyroid hormone, or reverse T3, an inactive thyroid hormone.

Testing for reverse T3 is vital for understanding the full picture.

"Normal" Thyroid Levels Are a Huge Risk

Having just slightly high TSH (above 1.48) is associated with high blood pressure and insulin resistance.

Cholesterol as a Thyroid Marker

Cholesterol is another marker of thyroid function.

We need thyroid hormones to break down circulating cholesterol and turn it into steroid hormones.

People with bad thyroid health often have high cholesterol. Thyroid therapy reduces cholesterol.

There are limitations to thyroid blood tests, but they can still be helpful when a proper panel is done, in proper context. I have written more about the right way to implement and assess lab testing.

At-Home Thyroid Testing: Morning Temperature and Heart Rate

Thyroid experts, before we were able to test hormones in the blood, used a few main assessments. One was morning temperature.

Morning temperature is taken by placing a thermometer under the arm, waiting 10 minutes, and recording the temperature, first thing in the morning.

If you are under 97.8°F (36.6°C) consistently, there's a good chance you're low on thyroid.

A heart rate under 70 is considered to be a key sign of hypothyroidism too, though of course this can be impacted by aerobic fitness.

Stress can also raise pulse rate, but if you're at rest and not stressed, it can be a helpful measure. I covered more in my related post on X.

What Lowers Thyroid Function: Stress, Diet, Liver and Inflammation

Stress

A huge problem for thyroid health is stress.

When you're stressed, your thyroid function is low, and vice versa.

Free fatty acids, which rise during stress, impede the binding of thyroid hormone to its receptor, rendering it useless.

Stress hormones like cortisol and adrenaline prevent T4 from being activated.

This is known as the "euthyroid sick syndrome," where your thyroid is making plenty of hormones, but you have low T3 and high reverse T3.

Lowering any chronic stress you have is going to be a top priority for optimizing thyroid function. I have written more about how to lower cortisol and calm chronic stress.

Poor antioxidant status is another factor.

Low Carb Diets

Low carb diets lower thyroid function.

Carbohydrates and insulin help to convert T4 into T3, and away from reverse T3.

This has been routinely documented in the research.

Cutting Calories

Cutting calories destroys thyroid function.

Reducing calories is known to slow down metabolism, in part by lowering T3 levels.

You need to eat enough to have healthy thyroid function. I have written more about why "eat less, move more" fails so often.

Liver Health

Liver health is vital for thyroid function.

The liver activates the bulk of T4 into T3.

If your liver is fatty or inflamed, you will inactivate more T4 into reverse T3.

Inflammation and Gut Endotoxin

Inflammation will ruin your thyroid health.

Various inflammatory mediators are known to suppress the thyroid axis at multiple levels.

One of the key inflammatory mediators is LPS (endotoxin), which actually comes from your gut.

So, optimizing your gut is also a top priority.

Nutrients, Leptin and Light That Boost Thyroid Function

Zinc

Zinc boosts thyroid function.

Zinc helps convert T4 into the active T3, lowering the inactive reverse T3.

This is likely due to zinc's antioxidant, anti-inflammatory properties, which I've covered at length elsewhere.

Selenium

Selenium is needed to convert T4 into T3, and supplementing during times of stress:

• Increases active thyroid hormone (T3)
• Decreases inactive reverse T3

Vitamin D

Vitamin D also boosts thyroid function.

Vitamin D aids in the expression of Dio2, which converts T4 into T3.

This reduces reverse T3, and increases T3.

Iodine

Iodine deficiency lowers IQ by 10-15 points, by causing hypothyroidism.

The thyroid hormones literally contain iodine.

Iodine is not something I suggest supplementing, since excess iodine can actually inhibit thyroid function.

Good salt, egg yolks and seafood is plenty.

Fluoride

Fluoride destroys thyroid function.

Since fluoride and iodine are the same class of element, fluoride will directly block iodine's uptake in the thyroid, lowering thyroid hormone output.

Fluoride also drives oxidative stress and inflammation, which we know lowers thyroid function.

Vitamin A

Vitamin A is required for thyroid function.

The nuclear thyroid hormone receptor needs vitamin A (retinol) to function properly.

Without it, your thyroid won't function at full capacity.

Leptin

Leptin also increases thyroid hormones.

As a marker of long term energy status, leptin increases thyroid hormone synthesis.

Leptin resistance will impair it, driving hunger and low metabolism.

Light and Near Infrared

Light increases thyroid function.

Bright light is vital for maintaining the circadian rhythm, which thyroid hormones operate on.

Near infrared light treats hypothyroidism. People using near infrared light:

• Needed to use less than half of their thyroid medication dose
• Suppressed their TSH
• Reduced their thyroid antibodies by over half

Infrared light helps to lower inflammation and restore energy production.

The sun has plenty of infrared light. I have written more about red light therapy for fatty liver disease.

Supplementing Thyroid Hormone With Natural Desiccated Thyroid (NDT)

Desiccated thyroid comes from the thyroid glands of pigs or cows, and is the traditional way of supplementing thyroid hormones.

Dosing

A grain (60 mg) is the unit of measurement for supplementation, containing ~40 mcg T4 and ~10 mcg T3.

A starting dose of a half grain is reasonable, and should be continued for 2-4 weeks before adjusting.

The hormones take around this long to stabilize.

I would take it with food to slow the absorption, or even split it into multiple doses with meals.

While some may require full replacement (4 to 5 grains), others find relief with as little as 15 mg (quarter grain).

Broda Barnes observed that his patients often required about two grains of thyroid to alleviate hypothyroid symptoms, occasionally needing more.

What to Track

As you use NDT, you should consistently track morning temperature.

Once you get to above 97.8°F and symptoms resolve, the correct dose has been found.

Signs You Took Too Much

If you get too fast of a heart rate, then you might have taken too much thyroid.

The amount taken should be reduced or discontinued entirely.

Effects of over stimulation should resolve in a few hours.

This type of response can also indicate low cholesterol or an issue with liver function, two systems that the thyroid depends on to do its good.

You may also need more nutrients, as the increased metabolic rate demands more resources.

Eat your liver, egg yolks, and oysters.

When Thyroid Does Nothing

Many people who should be candidates for supplementation find that thyroid does nothing for them, no matter how much they take.

In my experience, this always seems to be tied to an issue with the gut.

I would try to address this first.

Or, you just may not need it at all. You may need to address other factors.

Of course, supplementing thyroid is not the only way to improve thyroid function, but it seems like an appropriate strategy when other factors have been addressed.

Choosing a Brand

The brand matters a lot. Many products seem to be unreliable, or outright useless.

That's definitely been my experience. I've tried numerous products over the last few years.

The natural desiccated thyroid I have been using recently for myself and with clients:

Grass Fed Beef Thyroid Powder (NDT) from Life Giving Store

What the Results Show

Natural desiccated thyroid cuts fatigue symptoms by 60%.

People using it for hypothyroidism improved cognitive issues by 64%.

Energy over everything.

Figuring out all of this can be pretty difficult on your own.

Thyroid FAQ

What are the most common symptoms of poor thyroid function?

Being constantly tired, no matter how much you sleep. Poor thyroid function can also cause anxiety, depression, gut issues like SIBO, and low testosterone. If you have a health issue you can't explain, consider the thyroid as a prime cause.

Why isn't a TSH test enough to check my thyroid?

TSH does not tell you if you have enough T3, the active thyroid hormone. TSH can also be suppressed by things like stress, so it can be very misleading. A proper panel includes free and total T3 and T4, reverse T3, and cholesterol, read in proper context.

What is reverse T3?

T4 can be converted into either T3, the active thyroid hormone, or reverse T3, an inactive thyroid hormone. Stress, low carb diets and a fatty or inflamed liver push more T4 toward reverse T3.

How can I test my thyroid at home?

Place a thermometer under your arm first thing in the morning and wait 10 minutes. If you are consistently under 97.8°F (36.6°C), there's a good chance you're low on thyroid. A resting heart rate under 70 is also a key sign, though aerobic fitness affects it.

Does a low carb diet affect thyroid function?

Yes. Low carb diets lower thyroid function. Carbohydrates and insulin help convert T4 into T3 and away from reverse T3. Cutting calories also lowers T3 levels.

Should I supplement iodine for my thyroid?

I don't suggest it, since excess iodine can actually inhibit thyroid function. Good salt, egg yolks and seafood is plenty.

How much desiccated thyroid should I start with?

A half grain is a reasonable starting dose. Continue it for 2-4 weeks before adjusting, and track your morning temperature. Once you are above 97.8°F and symptoms resolve, the correct dose has been found.

Why does thyroid supplementation do nothing for me?

In my experience, this always seems to be tied to an issue with the gut. I would try to address this first. You may also not need it at all and need to address other factors.