# Thyroid

Category: Hormones

Thyroid hormone is necessary for respiration on the cellular level, and makes possible all higher biological functions. Without the metabolic efficiency, which is promoted by thyroid hormone, life couldn’t get much beyond the single-cell stage.

10 passages · 1 author · 1993–2021 · Most-cited: [Ray Peat](https://bioenergeticoracle.com/md/voices/ray-peat/index.md)

Canonical page: https://bioenergeticoracle.com/concepts/thyroid

## Synthesis

**Thyroid hormone** is the fundamental catalyst for oxidative metabolism, making possible all higher biological functions by enabling cells to use oxygen and produce carbon dioxide efficiently. [Source 1, 3] Peat argued that without the metabolic efficiency promoted by thyroid, life could not advance beyond the single-cell stage; it is the trigger for making *endless amounts of carbon dioxide*, which stabilizes the electronic balance in cells and sits at the heart of everything living. [Source 1, 4] The basic function of thyroid is to energize cells sufficiently to allow differentiation, preventing organisms from concentrating solely on eating and growing, which in humans can lead to tumors and malformations. [Source 3]

The active thyroid hormone is **triiodothyronine (T3)**, which is mostly produced in the liver from thyroxine (T4) depending on the availability of glucose, allowing a sensitive adjustment of metabolism to nutrition. [Source 9] When thyroxine is added to brain tissue in vitro, it suppresses respiration, but T3 increases respiration in any tissue. [Source 9] Peat emphasized that the medical community's reliance on **TSH measurement** as an indicator of hypothyroidism is problematic because TSH itself has *pro-inflammatory actions*, increasing fibrinogen and making blood more viscous; he considered a TSH between 0.0 and 0.4 the safe range. [Source 5] A major effect of thyroid is controlling the conversion of cholesterol into **pregnenolone**, **progesterone**, and other protective steroid hormones; excess cholesterol usually indicates thyroid or vitamin A deficiency. [Source 7, 9]

Thyroid function is intimately tied to the stress system. When thyroid is adequate, the pituitary and adrenals have an easy job; when thyroid is interfered with, the pituitary becomes a commander-in-chief driving stress hormones. [Source 6] Peat described a personal experience where his own metabolic rate was approximately three times normal due to stress, and taking thyroid brought it down to normal within days, allowing him to build muscle. [Source 2] He interpreted this through the lens of **magnesium** and ATP: when cells are de-energized, magnesium is lost and calcium associates with ADP, creating a stress state that thyroid can correct. [Source 2] Thyroid, especially T3, relieves depression by correcting a state of stress and lowering chronically elevated **cortisol**, making sleep efficient and restful rather than debilitating. [Source 8]

Several factors interfere with thyroid function. **Unsaturated oils** block proteolytic enzymes involved in hormone release, interfere with T4-to-T3 conversion in the liver, and inhibit tissue response to the hormone in proportion to the number of double bonds. [Source 9] A deficiency of polyunsaturated fatty acids is anti-estrogenic, partly by allowing the thyroid-stimulated liver to excrete estrogen. [Source 9] Stress hormones produced by allergy cause the liver to convert thyroxine to **reverse T3**, lowering thyroid function in a kind of defensive semi-hibernation. [Source 10] Peat noted that bad foods interfering with thyroid create hyperventilation at the very beginning; no matter how much you breathe, if your thyroid is underactive, your body experiences hyperventilation. [Source 4] Without adequate thyroid, tissues cannot function normally, leading to sluggishness, coldness, anemia, susceptibility to infections, heart disease, cancer, and premature aging. [Source 1]

## People also ask

### How does thyroid hormone affect cholesterol and steroid production?

Peat argued that thyroid controls the conversion of cholesterol into pregnenolone, progesterone, and other protective steroids, so excess cholesterol often signals thyroid or vitamin A deficiency.

### Why did Peat consider TSH testing unreliable for diagnosing hypothyroidism?

Peat noted that TSH itself has pro-inflammatory effects, raising fibrinogen and blood viscosity, and he considered a TSH between 0.0 and 0.4 the safe range rather than relying on standard lab norms.

### What role do unsaturated oils play in thyroid dysfunction?

The corpus describes how unsaturated oils block proteolytic enzymes needed for hormone release, interfere with T4-to-T3 conversion in the liver, and inhibit tissue response to thyroid in proportion to their double bonds.

## Related concepts

- [Cholesterol (HDL, LDL)](https://bioenergeticoracle.com/md/concepts/cholesterol-hdl-ldl/index.md)
- [Copper](https://bioenergeticoracle.com/md/concepts/copper/index.md)
- [Oxidation](https://bioenergeticoracle.com/md/concepts/oxidation/index.md)
- [T3 (Triiodothyronine)](https://bioenergeticoracle.com/md/concepts/t3-triiodothyronine/index.md)
- [Thyroid Stimulating Hormone (TSH)](https://bioenergeticoracle.com/md/concepts/thyroid-stimulating-hormone-tsh/index.md)
- [Adrenaline](https://bioenergeticoracle.com/md/concepts/adrenaline/index.md)

## Cited passages

Passage numbers match the `[Source N]` markers in the synthesis above.

### Source 1 — Glossary

Ray Peat · Glossary

> Thyroid
>
> Thyroid hormone is necessary for respiration on the cellular level, and makes possible all higher biological functions. Without the metabolic efficiency, which is promoted by thyroid hormone, life couldn’t get much beyond the single-cell stage.
>
> Without adequate thyroid, we become sluggish, clumsy, cold, anemic, and subject to infections, heart disease, headaches, cancer, and many other diseases, and seem to be prematurely aged, because none of our tissues can function normally.

### Source 2 — #43: Body Temperature, Inflammation, and Aging  |  Copper and Thyroid  |  mRNA Vaccines and Infertility

Ray Peat (with Danny Roddy) · Interview · Dec 18, 2020

> ## Thyroid, Magnesium, and Hibernation
>
> **Danny Roddy:** You mentioned Broda Barnes in your newsletter. Was he the inspiration for the first time you took thyroid?
>
> **Ray Peat:** His books came out in the early 1970s. I had been thinking about it for years, but since I had a much above-normal metabolic rate, I had to learn other things before I was willing to experiment with thyroid. I was on a BMR machine where you breathe oxygen while lying at rest. During the test, I had used up the oxygen before the test was over. It looked from the slope of the line like it was about three times the normal rate. I was aware of that for nine or ten years before I finally convinced myself to try taking thyroid. When I did, within a few days, my rate of metabolism had come down to approximately normal.
>
> **Danny Roddy:** Do you think your high natural rate of metabolism was from stress, and taking the thyroid lowered it?

### Source 3 — Interview with Raymond Peat, Ph.D.

Ray Peat · Interview · 2011 · http://l-i-g-h-t.com/files/east-west-the-thyroid.mp4

> **Josh Rubin:** In a lot of your articles and your science you’ve got a lot on the thyroid. So maybe you could enlighten us on why you study the thyroid so much and why you feel the thyroid hormone is so important or the most important hormone in the body?
>
> **Ray Peat:** Looking at life in general, plants and funguses and amoebas are the organisms that apparently don't need or don't want thyroid. But, as soon as you get to what we think as real animal life, that includes corals, coelenterates, echinoderms, mollusks, crustaceans, insects…just about everything that has an organization to it uses thyroid. And the basic function of thyroid is to energize cells and to give them enough energy and efficiency to allow them to differentiate so they just don't concentrate on eating and growing, the way plants, and amoebas and fungi and such do. So, if you look at some of the older experiments, like in an aquarium with developing frog eggs, as soon as the eggs would hatch in the tadpoles, they would either add an anti-thyroid chemical, or a little bit of thyroid hormone to the water. And if you added the anti-thyroid chemical, the tadpole would never turn into a frog; it would just get to be a huge tadpole. But if you added thyroid to the aquarium, the tiny hatchling tadpole would turn into a tiny, spider-like frog, just about the size of a fly, showing that the thyroid, which energizes the cells so that they use oxygen and produce a huge amount of energy. This energy allows the cells to realize their function. But when it comes on too early, they neglect to grow, so that, without thyroid, all you have is growth. And that's fine for amoebas, and mushrooms, and trees, and so on, but in humans, it can lead to things like tumors and malformations, and so on. So, the energy production is really the basis of all organized life. And that makes the thyroid, in a sense, the main gland. If you take out the pituitary gland, which people have talked about as the master gland....many different animals, if you remove that, and give them thyroid hormone, in some cases the animals live ten times as long as normal, usually about twice as long as normal, from the lack of the pituitary gland, as long as they had adequate thyroid.

### Source 4 — One Radio Network: Ray Peat with Patrick Timpone — September 21, 2021

Ray Peat · Interview · Sep 21, 2021

> **Patrick Timpone:** Wow. Fascinating. So what's with this thyroid? I mean, this seems like it's just everywhere, right? Thyroid issues. Do you have any theories on the spiritual or components of what's going on on planet Earth with a thyroid? I mean, why so much? Why so much?
>
> **Ray Peat:** It's the basic process of forming energy using oxygen and making carbon dioxide. Carbon dioxide is essential for every organism, bacteria, protozoa, whatever. They need carbon dioxide to go through the life process. processes, cell division and so on. And to make carbon dioxide, thyroid hormone is the trigger for making endless amounts of carbon dioxide. Carbon dioxide is what stabilizes the electronic balance in cells, so it's right at the heart of everything living.
>
> **Patrick Timpone:** So that's the idea of not over-breathing and retaining more carbon dioxide, even when exercising, right? Mm-hmm. Right? Wow. And so do you think then stress of modern-day life and over-breathing, mouth-breathing, that could be causing dispensing so much carbon dioxide, which could be affecting thyroid in our culture?

### Source 5 — Blood Pressure Regulation Heart Failure and Muscle Atrophy

Ray Peat · Interview · Jul 20, 2012 · https://www.youtube.com/watch?v=A8Ce3BdRpds

> **Herb Doctor:** So, good quality, organic grass-fed liver, beef, calf's or buffalo liver, is a good source of copper ?
>
> **Ray Peat:** Yah. And it's important to check your thyroid. The medical community for 30 years now has been relying on TSH measurement as an indicator of hypothyroidism; but they don't like to see the TSH get very low. But TSH is in itself the cause of many of the symptoms blamed on low thyroid. It's partly the lack of the respiratory effect of the thyroid hormone, but when your hormone is low, the TSH is high, and the TSH has pro-inflammatory actions, that for example, increase the fibrinogen in your blood, making your blood harder to circulate, more viscous.
>
> **Herb Doctor:** It's more easily clogged?
>
> **Ray Peat:** Yah. So it's really best for your circulatory system and nervous system, and so on, to have your TSH at least at the low end of normal. Which, according to the American Academy of Clinical Endocrinologists, is 0.3 to 3.0; but one study found that a population that had TSH below 0.4 had the lowest incidence of thyroid cancer. And so, somewhere between 0.0 to 0.4 would be the safe range probably.

### Source 6 — Politics & Science: Two Hour Fundraiser II

Ray Peat · Interview · Feb 22, 2012 · http://l-i-g-h-t.com/files/politics-science-two-hour-fundraiser-2.mp4

> ## Thyroid as the Master System
>
> **John Barkhausen:** I've heard the complaint about your writings before that "all he ever thinks is wrong with us is our thyroid," and somehow that's a put-down. How do you respond to that?
>
> **Ray Peat:** It doesn't apply just to people; it applies to all complex organisms practically. The difference between us and a fungus is that we've had a lot of thyroid and oxidative metabolism that the fungus hasn't benefited from. All of our functions are characterized by high-energy oxidative metabolism—the brain more than any other part. As you look at the animal kingdom, the outstanding thing is that their oxidative metabolism increases as they go up the so-called evolutionary scale. Oxygen is driving our existence, and our existence is culminating in a bigger, more expensive brain that other animals couldn't afford because their thyroid function wasn't adequate. It's really the essential thing. Given oxygen and sugar and a few other materials, thyroid is the catalyst for making things run right.
>
> **John Barkhausen:** The thyroid does seem like the master system in terms of energy production for everything.

### Source 7 — Brain and Tissue I and II KWAI 1080 Source Nutritional Show

Ray Peat · Interview · 2012

> **Damian Paul:** So, were you taking thyroid at the time?
>
> **Ray Peat:** No, I just happened to be a hyperthyroid person during that period.
>
> **Damian Paul:** You mentioned the hyper and hypo were kind of the same thing?
>
> **Ray Peat:** No. Doctors confuse hypothyroidism with hyper for various historical reasons. The basic thing that thyroid does is increase your oxidative metabolism. When the Synthroid product came on the market, only thyroxine - rather than the complete combination of T3 and T4 - when that came on the market, they wanted to say that thyroxine was the real thyroid hormone and it happens that it doesn't stimulate metabolism until it's turned into T3. And so for about 20 years, there was the doctrine that thyroid doesn't stimulate oxidative metabolism as its basic mechanism. But, in fact, the thyroxine interferes with the oxygen metabolism if it is out of balance [with T3]. It's really the increased consumption of oxygen and production of defensive energy systems that makes thyroid valuable. For example, the oxidative energy is used to convert cholesterol into pregnenolone and progesterone, DHA, male hormones and so on, to counteract estrogen as part of the defense against estrogen. So, if you have excess cholesterol, it's usually because your thyroid is deficient or your Vitamin A is deficient and you aren't converting it to the protective progesterone/testosterone hormones.

### Source 8 — Thought and energy, mood and metabolism

Ray Peat · Article · 2001

> Then, as the stress state disappears, the thyroid supplements will gradually begin to bring the metabolic rate, temperature, and pulse up to normal. When a normal body temperature is maintained by thyroid-supported respiration, rather than by the stress hormones, sleep is efficient.
>
> Thyroid, especially T3, has been commonly used in the treatment of depression, and there are many indications that, as it relieves the depression, it is also correcting a state of stress, lowering the cortisol which is typically chronically increased in depression, and making sleep restful, rather than debilitating. Women are especially susceptible to depression, diabetes, hypothyroidism, osteoporosis, Alzheimer's disease, and many other conditions that derive fairly directly from impaired energy metabolism. Some people have proposed that psychiatric problems are equivalent to "neural diabetes." "Syndrome X" (insulin resistance with heart symptoms) represents an advance toward seeing energy metabolism as the central biomedical issue.
>
> Adequate dietary protein, and the ability to use it efficiently, should have the highest priority in the treatment and prevention of nervous and emotional problems, regardless of whether the diagnosis is "bipolar disorder," "depression," "schizophrenia," "multiple sclerosis," "obsessive compulsive disorder," or other official psychiatric category. Without other nutrients, including sugar, much of the dietary protein is converted to energy, and without good thyroid function, protein can't be used properly. Whey, soy protein, and other industrial by-products sold as protein supplements aren't safe. Eating a variety of animal proteins, with some fruits and potatoes, is the safest way to prevent the metabolic disruptions caused by protein malnutrition.
>
> [references]

### Source 9 — Thyroid: Misconceptions

Ray Peat · Newsletter · Nov 1993

> It is the metabolically active derivative of thyroxine, somewhat as insulin is the activated form of proinsulin. When thyroxine is added to brain tissue in vitro, it suppresses respiration; but when triiodothyronine is added to any tissue, respiration is increased. Triiodothyronine (T3) is mostly produced in the liver, depending on the availability of glucose to the liver, allowing a sensitive adjustment of metabolism to nutrition.
>
> Armour thyroid, USP, is often said to be of imprecise dosage, but in fact every batch is biologically standardized, and studies have shown it to be reliably within 1 of the labeled potency. The best known brand of the supposedly chemically precise levothyroxine, however, was for a long time 30 below the labeled potency.
>
> If the liver is the main source of the thyroid problem, then thyroxine pills can make the problem worse, by suppressing the portion of T3 still coming from the thyroid gland. Armour thyroid, USP, Thyrolar, Euthroid, Proloid, and a few other products contain both thyroxine and T3, in approximately the proportion secreted by a normally functioning gland.
>
> Unsaturated oils interfere with thyroid function in several ways, including blocking the digestive proteolytic enzymes involved in the release of hormone from the globulin. Unsaturated fatty acids interfere with binding of the hormone to a transport protein, and with the conversion of T4 to T3 in the liver and in the pituitary. Linoleic and linolenic acids are roughly twice as toxic to these systems as oleic acid is. The tissue response to the hormone is inhibited by unsaturated fats in proportion to the number of double bonds in the fat. A deficiency of polyunsaturated fatty acids is anti-estrogenic, partly by allowing the thyroid-stimulated liver to excrete estrogen, and partly by failing to activate the pituitary secretion of gonadotrophins.
>
> G. W. Crile found that the basal metabolism of the people in Yucatan, where coconuts are a staple food, is 125 of that of people in the United States. Animal experiments show that coconut oil added to a normal diet can lower serum cholesterol levels. There is a very reliable inverse relationship between the level of serum cholesterol and thyroid hormone action.

### Source 10 — Ray Peat Email Advice Depository — Post 537

Ray Peat · Email · Feb 27, 2019

> **Question:** Do you think its possible that if someone has been chronically eating foods they are allergic or sensitive to that the body might defensively lower thyroid function? Thanks!
>
> **Ray Peat:** The stress hormones produced by allergy cause the liver to convert thyroxine to reverse T3, lowering thyroid function, apparently in a kind of defensive semi-hibernation.

_Generated 2026-07-20 from the Bioenergetic Oracle corpus._