Your Thyroid is Connected to Your Liver

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The Pure TheraPro Team

The Pure TheraPro Education Team is comprised of researchers from diverse backgrounds including nutrition, functional medicine, fitness, supplement formulation & food science. All articles have been reviewed for content, accuracy, and compliance by a holistic integrative nutritionist certified by an accredited institution.
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If you’re taking a synthetic T4 only thyroid medication and still experiencing symptoms (fatigue, hair loss, weight gain, depression, lack of motivation, anxiety, gut issues, brain fog, etc), there might be a reason. Your thyroid is connected to your liver. That’s right. It’s also connected to your gut. And because of this, you might be one of many people out there who will never get well on a T4 only thyroid medication, especially if your gut and liver aren’t working up to their potential.

Here are some current and startling facts from the American Thyroid Association: 

An estimated 20 million Americans have thyroid disease,

About 60 percent of those with thyroid disease are unaware of their condition

Women are five to eight times more likely than men to have thyroid problems

Undiagnosed thyroid disease may put patients at risk for certain serious conditions, such as cardiovascular diseases, osteoporosis and infertility.

Most physicians will look at TSH (thyroid stimulating hormone) and solely use those results in determining the diagnosis of hypothyroidism. They will then prescribe synthetic T4 hormone, Synthroid or the generic levothyroxine. There are a few issues with this approach.

First, TSH measures how well your pituitary gland is working—it is not a true measurement of thyroid function.Thyroid dysfunction is extremely individual and intricate. A one size fits all approach to treatment will leave a vast majority of people untreated.

Second, everything in our bodies is woven together to create a mosaic of good or bad health. Although the American Thyroid Association states, “The causes of thyroid problems are largely unknown” research is showing that thyroid dysfunction is not limited to the thyroid; It is influenced by other bodily systems. If your thyroid isn’t working properly, you better believe this dis-ease can be found in other places, as well, which need to be traced and investigated to identify the root cause in order for the body to again function properly.

A physician who simply checks your TSH will tell you your numbers are “within range.” You may leave the office with a handful of prescriptions to alleviate symptoms. These might include PPIs for your heartburn, a beta blocker for your heart palpitations, a statin for your cholesterol levels, an SSRI for your depression and the list goes on.

What is T4? What is T3?

T4, which is the main ingredient in certain hypothyroid medications, is not the active thyroid hormone your body utilizes for all of its necessary function. T4 must first be converted to active T3. If it remains in the T4 form, it will not do much for you. T4 is like an old man in a rocking chair that can’t hear the music. When he can convert to active T3, that old man becomes Benjamin Button. It’s a life-changer. And where is T4 converted into active T3? Here’s where the mystery unfolds--it’s not just in the thyroid!

How well your body converts T4 to T3 is individual, and it is almost never evaluated when thyroid patients seek answers in mainstream medicine. A one size fits all approach to hypothyroidism by utilizing a T4 only pharmaceutical may not address the issue in most people.

When T4 doesn’t convert to T3 properly, symptoms of hypothyroidism result. Symptoms may include low B12 and vitamin D levels, poor iron absorption, anxiety and depression, high cortisol levels, weight loss resistance, weight gain, digestive issues, cold extremities, heart palpitations, migraines, mid-day fatigue, morning fatigue, dry skin and hair, thinning eyebrows, muscle and joint pains, high cholesterol and blood pressure, heart palpitations, hair loss, mood swings, brain fog and more.

So, what causes issues with this conversion process? Many, many factors that also need addressing to help boost thyroid function. Low conversion might be the result of chronic inflammation, nutrient deficiencies, leaky gut syndrome or other such intestinal dysbiosis, a congested, sluggish liver or elevated cortisol levels due to adrenal issues.

The conversion of T4 to T3 is key for proper thyroid function—but this conversion process relies heavily on your liver and gut.

Your liver is your master filter—removing toxins, helping to keep your blood clean. It also serves the duty of processing and metabolizing hormones. It’s a vicious cycle when your thyroid function is low, as it slows down your entire system. Your liver becomes sluggish and can’t complete this important function of converting T4 hormone into active T3, its usable form.

If your liver is sluggish, toxins can’t readily be removed, as well, including excess estrogen and xenoestrogens, which are chemicals that mimic estrogen in the body and may wreak havoc on the endocrine system. High levels of estrogen, also known as estrogen dominance, greatly affect the liver’s ability to convert T4 into T3 and impair the body’s ability to provide thyroid hormone down to the cellular level. The result? All the symptoms above. Your blood work might be “within range,” but your body isn’t utilizing active thyroid hormone properly—and you can feel it!


It’s not just your liver that’s carrying the weight of converting thyroid T4 hormone into active T3 for your body to utilize. Your intestines are responsible for approximately 20% of this conversion as a result of healthy gut bacteria. Poor digestion, chronic gut inflammation and dysbiosis will impact how well you can convert T4 into T3. If you’ve even been on one round of antibiotics in the last three years, this can impair your gut microbiome and negatively impact this conversion process. Processed food, gluten, alcohol, other prescription medications, sugar and  inflammatory foods can hinder T4 to T3 conversion by affecting gut health. This chronic gut inflammation may also affect the adrenal glands by producing more cortisol, which further impairs thyroid function and the body’s ability to utilize active T3 properly.

Nutrient deficiencies are common when your body is not properly utilizing T3 as a result of this sluggish conversion. A slower metabolic rate as a result of hypothyroidism impacts the gut and liver. Nutrient absorption is impaired in the digestive tract. Be sure to check your iron levels as well as vitamin D, B12 and selenium.



The highest concentration of selenium in the body in found in the thyroid, demonstrating selenium’s importance to creating optimal levels of thyroid hormones. A selenium deficiency is related to thyroid disease.  Studies show that selenium reduces TPO antibodies, which are the biomarker for autoimmune thyroid disease, such as Hashimoto’s. 90% of hypothyroid patients have Hashimoto’s Thyroiditis, which is an autoimmune disease that impacts thyroid function. Interestingly, selenium deficiency is also linked to gut issues, such as intestinal permeability (Leaky Gut Syndrome) and gut dysbiosis.

In addition, selenium is vital for proper liver function and is a powerful detoxifying agent, helping to maintain optimal levels of glutathione, which is the master antioxidant. A single Brazil nut contains 68 to 91 micrograms (mcg) of selenium. Eating just one brazil nut a day can provide the daily recommended adult allowance of 55 mcg.


As you can see, managing hypothyroidism is not as easy as checking TSH once every six months and keeping your lab values “inside the box.” You will not shake the symptoms of low thyroid function until your body is properly converting T4 to active T3 and utilizing it down to the cellular level. This effective utility is also influenced by methylation issues. The body’s inability to utilize certain B vitamins properly for cellular energy production and detoxification processes impacts your thyroid health and conversion ability. It’s estimated that approximately 50% of the population has a methylation issue and/or the MTHFR genetic mutation that impairs proper methylation function.


So, the next time you find yourself face to face with your endocrinologist or primary care physician, ask for a full thyroid panel. Most importantly, find out more about your free T3 levels. Although there is a wide reference range, most feel better when their free T3 levels are at the top 75% of the reference range.

Focus on nutrient deficiencies, supporting your liver and healing your gut naturally by avoiding inflammatory food triggers that affect gut health. Optimize your body’s elimination process with plenty of spring water to flush out toxins as well as a high-quality probiotic to replenish your microbiome. Seek alternatives to T4 only supplementation, such as natural desiccated thyroid hormone supplementation, which includes T3.