The thyroid hormone T3 is essential for a fast metabolism - but the...
Master Metabolism@lowmegatron
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Apr 28, 2025
~3 min read
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The thyroid hormone T3 is essential for a fast metabolism - but the thyroid gland only releases a little T3 - and a lot of inactive T4. The local conversion of T4 to T3 is critical for metabolic health.
Here are some tips for optimizing conversion. 🧵
Here are some tips for optimizing conversion. 🧵
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Eat enough.
Eat regularly.
Eat carbs.
Caloric restriction, fasting, and low-carb diets decrease thyroid hormone conversion. These diets program the body to survive famine, slowing the metabolism by creating reverse T3 instead of T3.
x.com/lowmegatron/st…
Eat regularly.
Eat carbs.
Caloric restriction, fasting, and low-carb diets decrease thyroid hormone conversion. These diets program the body to survive famine, slowing the metabolism by creating reverse T3 instead of T3.
x.com/lowmegatron/st…
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For people needing thyroid hormone, choosing the right type is key.
Reverse T3 blocks T3, but both are made from T4. The more T4 in the system, the greater the substrate for creating reverse T3. So, T4-only increases the likelihood of conversion issues.
T3-only can be used to deplete or prevent reverse T3 from getting too high. However, for many people, a combination of both works best.
Reverse T3 blocks T3, but both are made from T4. The more T4 in the system, the greater the substrate for creating reverse T3. So, T4-only increases the likelihood of conversion issues.
T3-only can be used to deplete or prevent reverse T3 from getting too high. However, for many people, a combination of both works best.
Master Metabolism@lowmegatron
Few things have such a powerful effect on health as correcting hypothyroidism.
Some people need thyroid hormone supplementation to get healthy and the type of thyroid hormone makes all the difference.
This thread explains different thyroid hormone supplements on the market. 🧵
Some people need thyroid hormone supplementation to get healthy and the type of thyroid hormone makes all the difference.
This thread explains different thyroid hormone supplements on the market. 🧵
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The liver is the biggest point of thyroid hormone conversion, making far more thyroid hormone (T3) than the thyroid itself.
Women, in particular, need to pay attention to the liver - especially the estrogen load on the organ. Estrogen takes up a lot of liver resources.
The Ray Peat Carrot Salad is very effective for some women as it can help absorb estrogen and other things that otherwise stress the liver and decrease conversion.
The recipe is simple:
One large shredded carrot.
A teaspoon of coconut or olive oil.
A teaspoon of vinegar.
The carrot should be shredded lengthwise to maximize the fiber in contact with the gastrointestinal system.
x.com/17440315631871…
Women, in particular, need to pay attention to the liver - especially the estrogen load on the organ. Estrogen takes up a lot of liver resources.
The Ray Peat Carrot Salad is very effective for some women as it can help absorb estrogen and other things that otherwise stress the liver and decrease conversion.
The recipe is simple:
One large shredded carrot.
A teaspoon of coconut or olive oil.
A teaspoon of vinegar.
The carrot should be shredded lengthwise to maximize the fiber in contact with the gastrointestinal system.
x.com/17440315631871…
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Zinc is an essential and often overlooked factor in thyroid hormone conversion. People at higher risk for zinc deficiency include older adults, pregnant and lactating women, vegetarians and vegans, and individuals with gastrointestinal disorders. Oysters are a great source of zinc.
Master Metabolism@lowmegatron
Zinc can help offset the negative effects of overtraining on thyroid and testosterone.
“TT3, TT4, FT3, and total and free testosterone levels decreased after exercise compared to resting levels before supplementation. Both the resting and fatigue hormone values were higher after 4 weeks of supplementation than before supplementation.”
“TT3, TT4, FT3, and total and free testosterone levels decreased after exercise compared to resting levels before supplementation. Both the resting and fatigue hormone values were higher after 4 weeks of supplementation than before supplementation.”
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Exercise stress can decrease thyroid hormone conversion, partly by increasing stress hormones. Combining dietary stresses like those mentioned earlier can amplify the anti-thyroid effects.
I'm not saying don't exercise, but do recognize that it is stressful. At a certain point, excess stress will downregulate the thyroid.
Build, don't break.
x.com/17440315631871…
I'm not saying don't exercise, but do recognize that it is stressful. At a certain point, excess stress will downregulate the thyroid.
Build, don't break.
x.com/17440315631871…
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Decades ago, Dr. Broda Barnes noted that high-protein diets increase the need for thyroid supplementation in his hypothyroid patients.
High-protein diets tend to increase stress hormones that lower conversion, as those stress hormones are required to turn amino acids into glucose. Some amino acids like methionine also seem to inhibit thyroid hormone conversion. DIO2 converts T4 to T3.
High-protein diets tend to increase stress hormones that lower conversion, as those stress hormones are required to turn amino acids into glucose. Some amino acids like methionine also seem to inhibit thyroid hormone conversion. DIO2 converts T4 to T3.
Master Metabolism@lowmegatron
“It seems clear that a diet quite high in protein utilizes available thyroid hormone. Two studies in the medical literature indicate that excess protein lowers the basal metabolism.” Broda O. Barnes
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Mold and other pathogens cause nonthyroidal illness, also called euthyroid sick syndrome. It is characterized by low T3, low T3/rT3 ratio, and a normal TSH. T4 may be normal or high.
It seems that part of this effect is mediated by the release of large amounts of free fatty acids into the blood, inhibiting conversion to T3 and elevating reverse T3.
These polyunsaturated fats are linoleic, arachidonic, and linolenic acid, omega-6s, and omega-3s. They have broad-ranging anti-thyroid effects. Seed oils, pork, and poultry are major sources.
It seems that part of this effect is mediated by the release of large amounts of free fatty acids into the blood, inhibiting conversion to T3 and elevating reverse T3.
These polyunsaturated fats are linoleic, arachidonic, and linolenic acid, omega-6s, and omega-3s. They have broad-ranging anti-thyroid effects. Seed oils, pork, and poultry are major sources.
Master Metabolism@lowmegatron
Polyunsaturated fats happen to be very general and effective blockers of thyroid function. A whole series of papers was published in the French Annals of Endocrinology showing that the secretion of the thyroid gland is inhibited by polyunsaturated fats. The ability of transport proteins in the blood to carry thyroid hormone was blocked by these same unsaturated fats, and the more unsaturated, the more perfect the blocking. Ray Peat
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Selenium is essential for thyroid hormone conversion, and correcting a deficiency seems to prevent and somewhat reverse general thyroid dysfunction. 200-400 mcg per day seems sufficient.
x.com/17440315631871…
x.com/17440315631871…
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Magnesium is another often-deficient nutrient needed for thyroid hormone conversion. Many people only get 2-300 mg daily, but they could see huge benefits from getting 3-4 times this. Magnesium helps lower stress hormones that decrease thyroid hormone conversion.
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