Demystifying Thyroid Supplementation

"When doubt exists, a trial of thyroid supplementation may be the most useful diagnostic tool." — M.B. James (1981)

Originally posted October 2017.

[New 2023] Bioenergetic Basics #1: Successfully Using a Thyroid Supplement of T3 and T4 https://dannyroddy.substack.com/p/bioenergetic-basics-1-successfully

[New 2024] Bioenergetic Basics #12: Five Ways to Goof-Up Thyroid Hormone Supplementation https://dannyroddy.substack.com/p/bioenergetic-basics-12-five-ways

Continuing the trend of concretizing some thoughts on popular questions, I wanted to put together a little "thyroid primer." For clarity, I've split this post into three sections: 1) symptoms, 2) determining the correct dose, 3) T3/T4 ratio, and 4) troubleshooting. Please ask questions below if something is not clear or I left something out. 

Part I: Symptoms

“Oral or armpit temperature, in the morning before getting out of bed, should be around 98F, and it should rise to 98.6F by mid-morning... Healthy populations have an average resting pulse of about 85 per minute. Especially in hot weather it is useful to consider both temperature and pulse rate.” — Ray Peat

“The proper dosage for any individual is the minimum needed to relieve symptoms. Most commonly, in adults, this is two grains; three grains sometimes are needed. rarely four grains may be required. The basal temperature may still be a little low, but one is treating symptoms, not temperature per se.” —Broda Barnes

In addition to grabbing the resting pulse rate and underarm temperature in the morning and afternoon, it's probably good to become familiar with the classical low thyroid symptoms. Here is a shortlist from a 1981 paper by James, et al.

While I can identify with many symptoms on that list, famous "thyroidologist" Broda Barnes pointed out that people express symptoms differently, which is why the pulse rate and temperature are so valuable as health markers in times of uncertainty:

“No single symptom has been found which would apply to every person with low metabolism. Some have fatigue, some have cutaneous disorders, some have dry skin, some have nervousness, some have menstrual difficulties, some have dry hair and some have other symptoms, but none of these signs could be considered reliable in all cases.” — Broda Barnes

Image: Thyroid supplementation before and after

Part II: Determining The Right Dose

“When doubt exists, a trial of thyroid supplementation may be the most useful diagnostic tool.” — M.B. James (1981) 

“A therapeutic trial was the final test of the validity of the diagnosis: If the patient's symptoms disappeared as his temperature and pulse rate and food intake were normalized, the diagnostic hypothesis was confirmed... Whatever objective indicator was used, whether it was basal metabolic rate, or serum cholesterol, or core temperature, or reflex relaxation rate, a simple chart would graphically indicate the rate of recovery toward normal health.” — Ray Peat

“...An eighth to a fourth of a [Cynoplus] tablet would be a reasonable amount to start with; thyroxine’s half-life in the body is two weeks, so the effect is cumulative, and if you get the desired effects in less than two weeks the dose should probably be reduced.” — Ray Peat

“It’s best to absorb it slowly, to imitate the normal pattern of secretion, and food helps to slow the absorption.” — Ray Peat

“Sensitivities and requirements vary widely. I've known people who temporarily needed 500 mg of Armour even in the summer, but usually the summer requirement is a fourth of the winter requirement. For some people, 15 mg of Armour was enough, and for some 1 mcg of Cytomel was an effective dose.” — Ray Peat

If a person feels like they have a general understanding of the problem they're experiencing along with what thyroid therapy has to offer, I don't think it's unreasonable to investigate obtaining thyroid hormone. Usually, people get thyroid hormone from their doctors, although some people purchase it from online pharmacies, for example, here and here. 

Thyroid hormone is measured in “grains” with one grain being about ~12.5 micrograms of T3 and ~50 micrograms of T4. A healthy person usually makes about four grains of thyroid per day. 

• One grain of thyroid = 12.5 micrograms of T3 and 50 micrograms of T4

• One cynoplus tablet = 30 micrograms of T3 and 120 micrograms of T4 (or 2.2 grains)

Broda Barnes noted that his patients usually needed about two grains:

“Most commonly, in adults, this is two grains [to correct hypothyroid symptoms]; three grains sometimes are needed, rarely four grains may be required.” — Broda Barnes

When I asked Ray in 2014 if a person ever needed more than two grains, he replied:

“In general, no, but I have known a few people who needed much larger amounts for a while.” — Ray Peat

If the body only makes a few micrograms of T3 per hour, it’s critical to not take more than 5-10 micrograms of T3 per dose (with food):

“...Each dose shouldn't contain much more than maybe 10 mcg of T3. If you're going to take say 10 mcg of Cytomel and 40 mcg of T4 then you should break it so that each dose doesn't give you much more than 10 mcg of T3.” Ray Peat

Besides taking a slow and methodical approach, something I think that is very important to remember is that the half-life of T4 (thyroxine) is two weeks, and thus the full potential of any given dose isn't 'realized' until the end of the second week.

I've talked to many people who told me that they changed their thyroid dose every few days, which I imagine makes things ridiculously confusing, if not impossible, to figure out. Whatever the dose, it should be maintained for at least two weeks before judging the effects. 

Part III: T3/T4 Ratio

While Broda Barnes treated his patients with the standard 1:4 ratio of T3:T4, something unique about Ray Peat is his emphasis on T3. For example, in the article, Thyroid: Therapies, Confusion, and Fraud, Ray mentions that a 1:3 ratio of T3:T4 is “brain favorable”:

“These observations suggest to me that the blood’s T3:T4 ratio would be very 'brain favorable' if it approached more closely to the ratio formed in the thyroid gland, and secreted into the blood. Although most synthetic combination thyroid products now use a ratio of four T4 to one T3, many people feel that their memory and thinking are clearer when they take a ratio of about three to one. More active metabolism probably keeps the blood ratio of T3 to T4 relatively high, with the liver consuming T4 at about the same rate that T3 is used.” — Ray Peat

In practice, this usually means adding additional T3 in the form of Cynomel to the dose of Cynoplus or another combination thyroid brand. For example, for myself, I usually take small amounts of T3 during the day and save the combination product (T3 and T4) for the evening.

Part VI: Troubleshooting

“One mistake which has been made in the past has been to start thyroid therapy with excessive amounts. Another has been to give up too soon to expect immediate results, immediate disappearance of symptoms. And still a third has been to stop thyroid therapy because the patient has become nervous and the nervousness has been thought to be the result of too much thyroid. If the basal temperature is still low or within the normal range, it is a clear indication that the nervousness and other symptoms are not coming from too much thyroid and thyroid therapy should continue while an effort is made to overcome or adjust to what is really the disturbing factor.” — Broda Barnes (1973) 

“That sort of sudden adrenaline effect can happen when there’s something essential missing in the diet, while the requirements are increased by using thyroid. Deficiencies of protein, magnesium, calcium, and the B vitamins are most likely. Too much phosphate and too little carbohydrate are other possibilities.” … “When you first start taking thyroid again, your tissues will need some extra magnesium...” — Ray Peat

“Administration of thyroid to these patients, in the absence of a vitamin B supplement, usually caused exacerbation of the signs and symptoms of deficiency without significant change in the metabolic rate.” — Morton Biskind (1946)

With the general understanding that thyroid is an effective broad-range therapy with a long historical track record of safety, a person can start thinking about potential possibilities if thyroid therapy does not go as expected. Some of the most common road bumps seem to be:

• Vitamin D deficiency

• A diet deficient in protein or B vitamins

• A diet deficient in calcium and excessive in phosphate

• A diet deficient in carbohydrate

• A diet deficient in calories

• Ruminant liver-avoidance

• Oyster-avoidance

• Infection, which is more common in hypothyroid people

• Cholesterol deficiency (requires a lab test)

One of the reasons I'm bullish on finding a way to regularly consume liver and oysters is that increasing the rate of metabolism can quickly increase a person's nutritional needs. I think attempting to replicate the nutrition found in liver and oysters with supplements is a fool's errand with each new supplement introduced as a possible allergen. Vitamins D and K can be safely used topically as Ray and I talk about in this interview. 

“When your intestine is extremely sensitive, the excipients and contaminants in a pregnenolone tablet could cause bad symptoms; the only supplements that are very safe to take orally are aspirin, cascara, some kinds of thyroid, small amounts of penicillin (30 mg), cyproheptadine (one half to one milligram), and progesterone. Vitamin A and DHEA on the skin are safe, but you should put the vitamin A on your lower legs, and wash your hands so that none of it gets on your lips.” — Ray Peat

Part V: Final Thoughts

A final consideration with using a thyroid supplement is a person's climate. For example, while I need about 1/4 of a Cynoplus tablet and some extra T3 while I'm in Mexico, I needed almost an entire Cynoplus tablet when I visited cold Japan. 

Also, for what it's worth, I've been using cynoplus and cynomel since about 2011 and still feel like I'm learning new things about them. For myself, incorporating thyroid was tricky due to an infection and extreme malnourishment (after two years of zero-carb), but the journey to respond to thyroid normally revealed several other problems that I wouldn't have known about otherwise. 

I hope this helps. Cheers.