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4 Reasons Why Taking Thyroid Hormones May Be a Bad Idea

Written by Joe Cohen, BS | Last updated:

Thyroid hormones may be necessary, but any imbalances can cause major issues in your body. Understand the potential drawbacks of thyroid hormones.

Main Thyroid Hormone Functions

  • Breathing
  • Energy production
  • Heart rate
  • Cognitive function
  • Mood
  • Body weight
  • Muscle strength
  • Menstrual cycles
  • Body temperature
  • Cholesterol levels
  • Growth and development
  • Intestinal flow
  • Digestion

Hyperthyroid Symptoms

Hyperthyroid (too much T3 or T4) symptoms include:

  • Sweating or sensitivity to high temperatures
  • Hair loss
  • Faster heart rate
  • Diarrhea
  • Weight loss
  • Missed or light menstrual periods

Hypothyroid Symptoms

Low levels of T3 cause a slower heart rate, constipation, and potentially weight gain.

Hypothyroidism (too little T3 or T4) symptoms include:

  • Trouble sleeping and waking up earlier than you want
  • Tiredness and fatigue
  • Difficulty concentrating
    • Impaired memory
  • Depression
  • Anxiety
  • Sensitivity to cold temperature
  • Frequent, heavy periods
  • Constipation
  • Elevated blood cholesterol
  • Slowed heart rate
  • Weight gain
  • Joint and muscle pain
  • Dry skin and hair

Thyroid Hormone Test

You can request that your doctor test your thyroid hormones. Conventional doctors will look at high or low thyroid hormone levels and not mention anything. Sometimes, a lab result may be in the reference range, but not actually be in the optimal range. Reference ranges are not the same as optimal ranges. This is why even thyroid hormones in the ‘normal’ range can be unhealthy and indicate that certain processes in the body aren’t optimal.

4 Reasons Why Taking a Thyroid Hormone May Not Be a Good Idea

1) Low Levels May Lower Inflammation

Joe’s experience: I’ve noticed that whenever I’m in a hyperthyroid state, I’m more sensitive to an autoimmune attack. When I induce hypothyroidism, I’m immune to such an attack, so there might be an advantage to being hypothyroid.

The immune system controls thyroid hormone levels through the pituitary-thyroid axis and protein kinase C transmission [1, 2].

Conversely, thyroid hormones control immune function [3, 4].

Hypothyroidism is linked to immune deficiency [5].

2) Increases Inflammation

Thyroid hormones also elevate cytokines like IL-6. The more thyroid hormone there is, the higher IL-6 gets [6].

Inflammatory cytokines like macrophage inflammatory protein 1alpha and IL-1beta contribute to hypothyroidism. However, an increase in pro-inflammatory cytokines such as TNF-alpha and nitric oxide synthase may be caused by increased T3 [4].

Thyroid hormones are potent activators of energy production. We feel a boost of energy, but our chronic inflammation also goes up.

When we have chronic inflammation, the body is smart to lower our thyroid hormones a bit so that the inflammation is reduced. It’s called balance.

3) Activates mTOR and Worsens Th17 Dominance

mTOR, which increases energy production, also stimulates the immune system and increases inflammation. To learn more about diseases caused by mTOR activation, read this post.

If you’re fighting a pathogen, then revving up your immune system is probably a good idea (if you also use other means to kill it), but if your inflammation is from lectins or some other inflammatory agent, then it’s not a good idea to stimulate your immune system even more.

Indeed, one of the best ways to inhibit chronic inflammation is by inhibiting mTOR.

This pathway is particularly important to people with Hashimoto’s and Grave’s, because both of these diseases originate from elevated Th17 inflammation, which is caused by mTOR activation.

Thyroid hormones are activators of mTOR [7, 8].

4) Increases Oxidative Stress

Perhaps the worst effect of thyroid hormones is that they increase the worst kind of free radical: superoxide. This happens with the increase of the energy production of immune cells (and others) [9].

Not only do hormones increase superoxide, but they also decrease the enzyme to break down superoxide (SOD) [10].

Increased oxidative stress may accelerate aging, so it makes sense that lower thyroid hormone levels are associated with longevity [11].

In a cross-sectional study, longevity correlates with higher TSH levels, as well as lower T3 and T4 levels among people who live exceptionally long (beyond 89 years for males and 91 years for females) [12].

When Taking Thyroid Hormone Is Necessary

I would never suggest not experimenting with thyroid hormones, but it should be done after you’ve taken all of the tests to measure inflammation, oxidative stress, and adiponectin (for lectin sensitivity). Perhaps try the lectin avoidance diet first, if possible.

It would be wise to experiment with many other things first before turning to thyroid hormones.

If you’ve tried everything and you still have low thyroid hormones, then experiment by taking it and continue with it only if you see a significant benefit (in the long run as well).

I would much rather people take TRH for a sluggish thyroid, although it is quite expensive.

Thyroid hormones are indeed a godsend for people with advanced Hashimoto’s, head traumas, or other similar concerns.

However, before taking thyroid hormones, you want to make sure that either your thyroid antibodies are high or that your thyroid hormones are significantly below the standard (not borderline).

Irregular Thyroid Hormone Levels?

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About the Author

Joe Cohen, BS

Joe Cohen, BS

Joe Cohen flipped the script on conventional and alternative medicine…and it worked. Growing up, he suffered from inflammation, brain fog, fatigue, digestive problems, insomnia, anxiety, and other issues that were poorly understood in traditional healthcare. Frustrated by the lack of good information and tools, Joe decided to embark on a learning journey to decode his DNA and track his biomarkers in search of better health. Through this personalized approach, he discovered his genetic weaknesses and was able to optimize his health 10X better than he ever thought was possible. Based on his own health success, he went on to found SelfDecode, the world’s first direct-to-consumer DNA analyzer & precision health tool that utilizes AI-driven polygenic risk scoring to produce accurate insights and health recommendations. Today, SelfDecode has helped over 100,000 people understand how to get healthier using their DNA and labs.
Joe is a thriving entrepreneur, with a mission of empowering people to take advantage of the precision health revolution and uncover insights from their DNA and biomarkers so that we can all feel great all of the time.


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