# Thyroid Medication (NDT)

Category: Drugs & Compounds

Also known as: thyroid medication, NDT, natural desiccated thyroid, desiccated thyroid, Cynomel

Natural desiccated thyroid (NDT) is a glandular supplement derived from animal thyroid tissue, which Peat considered the most physiologically appropriate replacement for a missing or underactive gland because it provides the full spectrum of thyroid-related proteins and…

11 passages · 3 authors · 2013–2022 · Most-cited: [Ray Peat](https://bioenergeticoracle.com/md/voices/ray-peat/index.md)

Canonical page: https://bioenergeticoracle.com/concepts/thyroid-medication-ndt

## Synthesis

**Natural desiccated thyroid (NDT)** is a glandular supplement derived from animal thyroid tissue, which Peat considered the most physiologically appropriate replacement for a missing or underactive gland because it provides the full spectrum of thyroid-related proteins and hormones. [Source 1, 3] The working human thyroid gland produces the equivalent of about **4 grains** of desiccated thyroid per day, roughly 70% of which is the pro-hormone thyroxine (T4), allowing the liver to generate the active T3 hormone as needed when it is well-nourished and not inhibited by substances like *polyunsaturated fats* or estrogen. [Source 1] Crucially, the glandular material itself does not contain free, active hormone; it is composed of **thyroglobulin**, a protein that releases T4 and T3 only upon digestion, which makes its absorption more gradual than that of pure synthetic hormones. [Source 2, 3]

The pharmacokinetics of NDT differ sharply from isolated T3. Peat explained that taking even 10 micrograms of pure T3 at once signals the liver that it is being overdosed, triggering the production of enzymes that rapidly destroy the hormone. [Source 2] Because NDT requires enzymatic breakdown, its hormonal release is inherently time-released, making it safer to take with meals and less likely to provoke this hepatic inactivation response. [Source 2] Peat advised dividing the daily dose of desiccated thyroid, taking some with each meal and at bedtime, to prevent the blood level of active hormone from spiking too high at any single moment. [Source 1] This contrasts with the common pharmaceutical advice to take thyroid on an empty stomach, a practice Peat noted had been promoted for over 50 years but was unnecessary for NDT. [Source 4]

Product quality and formulation are persistent concerns. Peat stated that most glandular products on the market are not what they claim to be, though he acknowledged that **Armour thyroid, USP**, currently seems acceptable. [Source 6] He was highly critical of the industry, noting that thyroid supplements are often "compounded by crooks, morons, and pharmacists," and that the original Armour formula was altered after its acquisition by Revlon and subsequent companies, with the extraction of **thyrocalcitonin** for separate sale leaving little of the original substance intact. [Source 7] Roddy and Littlewood have corroborated this variability, observing that brands like Nature-Throid and WP Thyroid experienced a noticeable drop in quality and effectiveness around 2019-2020, while the liquid NDT product **Tyromax** produced good responses for some users. [Source 5] Dinkov has written that NDT occupies a legally murky status in the U.S., which has so far allowed vendors to operate, whereas isolated T3 is a controlled substance and clearly illegal to sell as a supplement. [Source 9]

For those unable to obtain reliable NDT, Peat recommended the Mexican pharmaceutical **Cynoplus** (also called Sinoplus), a synthetic tablet with a 4:1 ratio of T4 to T3, which he described as the closest imitation of traditional Armour thyroid. [Source 8, 10] A single Cynoplus tablet is slightly more potent than a 2-grain equivalent of desiccated thyroid, and Peat insisted that dosing begin with no more than one-eighth to one-fourth of a tablet, as starting with excessive amounts has created an epidemic of *thyroid hormone intolerance syndrome*. [Source 4, 10] He emphasized that a person's requirements are highly variable, increasing greatly during winter at high latitudes, and that the effects of any product must be monitored by watching pulse rate, temperature, and symptoms. [Source 7] Roddy has extended this caution, noting that even a tiny dose of NDT can provoke anxiety and jitteriness if there is an underlying nutritional deficiency—particularly of protein, magnesium, calcium, or B vitamins—or if **total cholesterol** is dangerously low, as thyroid will further reduce this adaptive substance. [Source 11]

## People also ask

### Why did Peat consider NDT safer than pure T3?

Peat argued that NDT requires enzymatic breakdown to release hormones, creating a time-released effect that avoids the rapid liver inactivation triggered by even small doses of isolated T3.

### What nutritional deficiencies can make NDT cause anxiety?

The corpus notes that even tiny doses of NDT can provoke anxiety and jitteriness if there is an underlying deficiency in protein, magnesium, calcium, or B vitamins, or if total cholesterol is dangerously low.

### What synthetic alternative did Peat recommend when reliable NDT is unavailable?

Peat recommended the Mexican pharmaceutical Cynoplus, a synthetic tablet with a 4:1 ratio of T4 to T3, which he described as the closest imitation of traditional Armour thyroid.

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## Cited passages

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

### Source 1 — Ray Peat Email Advice Depository — Post 55

Ray Peat · Email · Mar 14, 2013

> **Question:** Talking about taking thyroid medication after thyroidectomy (I'm currently on 4 grains NDT ):
>
> **Ray Peat:** The working thyroid gland produces about the equivalent of 4 grains of desiccated thyroid per day, and that is about 70% thyroxine, T4, which allows the liver to make as much of the active T3 hormone as needed (if it is well nourished, and not blocked by PUFA or estrogen or other inhibitor). So taking that amount makes up for what your gland would be producing; by suppressing TSH, which stimulates the growth and activity of the thyroid, it also protects against the recurrence of cancer if it wasn't all removed (some types of cancer were treated just by supplementing thyroid, without surgery). Since the desiccated thyroid is made available by being digested, it's best to divide the day's dose, with some at each meal and at bedtime, so that the amount of active hormone entering the blood isn't too high at any time.

### Source 2 — One Radio Network: Ray Peat with Patrick Timpone — May 16, 2022

Ray Peat · Interview · May 16, 2022

> **Ray Peat:** No.
>
> **Patrick Timpone:** No, you never did that. So let's go back to this person. So on her liver being clogged up yellow, could that be liver toxicity? So you'd want to look at the liver enzymes you would recommend her to arrive and see what's going on?
>
> **Ray Peat:** Yeah. And If the liver is actually getting blocked up, that requires usually something to make your intestine more active and less inflamed. And usually a thyroid supplement goes with correcting the liver enzyme excess.
>
> **Patrick Timpone:** Mm-hmm. Oh, the question we had on the thyroid, he wrote back and said, NTD is natural desiccated thyroid. So let's see what he asked here. Okay. Let me see if I can find it here. Oh, okay. Also, he said, can something... Someone take their dose of natural desiccated thyroid once a day with a meal as opposed to synthetic T3, which is better to take spread throughout the day. That was his question.
>
> **Ray Peat:** Yeah, the natural thyroid gland produces when it's digested both T4 and T3, but it contains none of those as an actual dose. ingredient that are produced by the digestive enzymes so touching it with food there will be a gradual release of those things and so it doesn't hit you doesn't hit your liver for example as evidence that you're poisoned by an excess of something where if you take too much T3 even 10 micrograms at once of pure T3 signals your liver that you're overdosed at that moment and so your liver begins producing the enzyme to break down the T3 so if you do that regularly the liver becomes very active in destroying T3. That's why it's important to take little bits of it gradually during the day.

### Source 3 — Ray Peat Email Advice Depository — Post 253

Ray Peat · Email · Aug 10, 2016

> ## Thread 7
>
> **Question:** [Topical thyroid (NDT ) for male pattern baldness] In a radio interview, you mentioned the use of caffeine in ethanol solution as a topical remedy for hairloss or male pattern baldness. I have access to a natural desiccated thyroid supplement (NDT) that's in a solution of DMSO and ethanol. Would applying this to the scalp be superior to applying caffeine to the scalp?
>
> **Ray Peat:** Desiccated thyroid gland doesn’t contain any free hormone; the gland contains thyroglobulin, a protein, which when digested releases the hormones.

### Source 4 — One Radio Network: Ray Peat with Patrick Timpone — May 16, 2022

Ray Peat · Interview · May 16, 2022

> **Ray Peat:** Well, yeah, never take more than maximum would be a fourth of a CNO+. better start with an eighth of a tablet.
>
> **Patrick Timpone:** And then you would just do an eighth once a day and then work up a little bit to your temperature?
>
> **Ray Peat:** Yep. One of the emails that I get probably two or three every day is someone who has been told maybe by their bodybuilder expert to take a A whole tablet of Cytomel or Xenoplus. And the syndrome of intolerance to thyroid hormone, there's an epidemic of it right now.
>
> **Patrick Timpone:** Repeat that last part, please.
>
> **Ray Peat:** People telling me that they suffer from a syndrome of... hypersensitivity or intolerance to thyroid hormone because they've tried the absurdly high doses that so many people are recommending.
>
> **Patrick Timpone:** So the body just doesn't take to it? Just too much? Yeah. Wow. So what was the idea behind the bodybuilders? I don't want to give people any ideas. Why would they... Possibly recommend that kind of thing for bodybuilding.
>
> **Ray Peat:** Looking on the Internet, if you look up Cytomel or Xenomel, you see all of these bodybuilding people either selling it or recommending it.

### Source 5 — #72: Thyroid Hormone Troubleshooting | Ray Peat Wrong About Fish Oil? | Environmental Pollutants with Keith Littlewood

Danny Roddy · Interview · Oct 17, 2021 · https://open.spotify.com/episode/2pvY3WBlavoS7f4ugwmE09

> **Keith Littlewood:** No, I've only ever used bag breathing and kind of standard breathing techniques. But from what I gather from some people, it works really, really well.
>
> **Danny Roddy:** I haven't either, but my friends are going to a town over here and I think they're going to buy a tank, so I'm very excited. Okay, I think there was a question I was going to... Okay, never mind. Okay, this one, you kind of already addressed this, but what are your thoughts on NDT products such as Tyromax?
>
> **Keith Littlewood:** Yeah, I mean, I've taken Tyromax before and I had... I had some really good responses with it. It was muddied for me. Sorry to go off a story here, but I was being poisoned by my dishwasher. And I went to the hospital once, and I could have sworn it was the NDT. But after cutting out the dishwasher tablets, I kind of regained my health. And I blame Tyromax. But I think Tyromax is really, really good. And I think it's really just working out whether you do better with NDT. I know I can go on to an NDT as long as it doesn't have too many fillers in it. Like, you know, some of the other supplements are starting to not be as good quality. You know, I think when it was around Nature Throid and West Throid were really, really good at one point. And the quality seemed to drop off. just didn't do what they were doing anymore. I don't know if that's not the case. So it takes it to tie them with that brush. But I've certainly found like NDT like Tyromax really, really good. Again, it comes back to the question of sometimes digestive irritation, whether you can tolerate MCT as well. But it's really just an experiment. Find out what works best for you.

### Source 6 — Ray Peat Email Advice Depository — Post 648

Ray Peat · Email · Apr 12, 2021

> **Question:** what would you do if the cynoplus/cynomel supply chain gets disrupted, as it often does?
>
> **Ray Peat:** Novotiral has continued to be available. Most glandular products on the market aren’t what they claim to be, but Armour thyroid, USP, currently seems to be o.k.

### Source 7 — Email Exchanges — Thyroid

Ray Peat · Email · 2015

> Low ferritin is often a result of hypothyroidism. The need for thyroid increases greatly during the winter in high latitudes, for example when I needed half a grain in the summer, I had to increase it to two grains during the winter. When cholesterol is high, that can make it easier to adapt to a thyroid supplement, since the thyroid will stimulate the conversion of cholesterol into progesterone and the adrenal hormones.
>
> I have heard from a few people using it, one thinks it doesn't work , but I haven't heard enough details to form an opinion yet. [THIROYD by Greater Pharma]
>
> I use Cynoplus (contains T4 and T3) and Cynomel (T3 only) that I usually get from www.mymexicandrugstore.mx. There is only one size tablet, and a fourth of a tablet is a typical starting dose.
>
> Several of the commercially available products aren't well formulated, some are completely inactive. Cytomel's formulation has changed recently, so I'm not sure of its present potency. In areas with fluoridated water, taking a tablet with water can inactivate it. With good Cytomel, once a person has taken a very big dose, the liver produces enzymes to inactivate it quickly, so after 12 hours the blood level will become too low, and another big dose will be needed. Stress hormones are responsible for raising reverse T3, and just supplementing T3 is seldom enough to normalize the stress hormones, so continued use of large doses can maintain improved functioning, but at the risk of developing problems from the continued excess of those hormones.
>
> Armour thyroid, USP, was the standard thyroid used widely for about 80 years. Since ownership of the product name was bought by Revlon and then a series of other companies, I'm not sure anything of the simple original formula remains; maybe magnesium stearate, I haven't looked lately.
>
> A few years ago I had some communication from a pharmacist at Forest Pharmaceutical, and he said that over ten years ago they began having thyrocalcitonin extracted from the pig thyroid powder to sell separately as a new drug. I think that left stearic acid as the only ingredient the current product might have in common with traditional Armour thyroid, USP.

### Source 8 — One Radio Network: Ray Peat with Patrick Timpone — February 21, 2022

Ray Peat · Interview · Feb 21, 2022

> Take only synthetic thyroxine and that works fine for most young men, but for very few women it's appropriate because the estrogen blocks the ability to convert T4 to the active form of the hormone T3. So the thyroid that the conventional MD prescribes is okay? No, it's likely to be thyroxine. And so what kind could you get prescribed? What would you ask for? The last of the fairly reliable desiccated thyroid is armor. By chance you might come across one of the natural desiccated products that is well standardized, but it's a fairly random thing now. Wow. There's only one well-balanced product I know of, Seno Plus, which was a synthetic imitation of the old armor product. There are others containing both T3 and T4, but the balance is best in Seno Plus. Novoteral, it's a good product that has a little more T4 in relation to the T3. And the Seno Plus? And you like a little more T4 than the T3? Yeah, a good ratio is three or four to one, T4 to T3. And the Seno Plus, would that be the closest thing to a natural kind of piggy, a desiccated pig? Yeah, it's the closest thing to the traditional armor. And the Seno Plus, if I recall, the only place you can get that, can you get that in the United States or do we have to go to Mexico? Yeah, Mexican drugstores such as Farmacias Del Nino dot MX. Farmacio Del Nino, you can get Seno Plus. And would that be the same kind of dosage as the other similar? The pills come in a potency that's a little more than two grains equivalent of armor. Okay. So, it's good to start with one-eighth of a tablet, which is a quarter grain. And just kind of work your way up, huh? Mm-hmm. Interesting. Teresa, can you get too much progesterone and what symptoms would you have? I'm supplementing with progesterone in a couple of different forms, progesterone and a prescribed form. Oh, in vitamin E, it actually gets into your bloodstream through the digestive system. And too much of it will put you to sleep.

### Source 9 — IdeaLabs Forum Q&A — TyroMax

Georgi Dinkov · Forum Q&A · Dec 18, 2015

> **Georgi Dinkov:** (2015-12-19) Taking thyroid will lower endogenous production. I can't comment on how taking it for 3 days will affect you. Only a blood test can sow if it is suppressing your thyroid after 3 days, but pulse and temp should show you well enough if it's working. As far as the FDA, I am similar situation to American Biologics so I am hoping that if they are OK operating then so should be I. NDT legality is murky and so far FDA seems to be leaving the NDT vendors alone. Time will tell.
>
> **Forum User:** Why not a T3 product? NDT was already widely available. It was a good T3 only product that was lacking.
>
> **Georgi Dinkov:** (2015-12-19) Because isolated T3 is a controlled substance in the US and quite clearly illegal to sell as a supplement. NDT is murkier legally, but so far the other NDT vendors seem to be OK and I am hoping that I will be left alone too.
>
> **Forum User:** Can you give a little more information on the smell. Does it linger on the skin if taken topically? Or on the breath if taken orally?
>
> **Georgi Dinkov:** (2015-12-19) No it doesn't, at east not when I tried it. After topical application, once the product absorbs I can't smell it any more. Orally, there is no aftertaste whatsoever.

### Source 10 — One Radio Network: The True Nature of a Virus (September 21, 2020)

Ray Peat · Interview · Sep 21, 2020

> **Ray Peat:** Stronger than a two-grain tablet of armor or one of the standard glandulars. It's equivalent to about 2.2 or 3 tenths of a grain per cytoplus.
>
> **Patrick Timpone:** So the cytoplus is just the three. Is that correct if I remember? T3?
>
> **Ray Peat:** No, it's T4. four parts to one part of T3.
>
> **Patrick Timpone:** Okay. And that equals to a full...
>
> **Ray Peat:** More than two grains. Two grains.
>
> **Patrick Timpone:** That's 120 milligrams of a nature throid. Wow.
>
> **Ray Peat:** Right. About 130 or 140. Yeah.
>
> **Patrick Timpone:** So you wouldn't want to use the SenoPlus if you're just starting, right?
>
> **Ray Peat:** Yeah, it's good to start on a fourth of a tablet, which is roughly like a half a grain.
>
> **Patrick Timpone:** Do I need a U.S. script, or can I get this in the Medicina Mexico site?
>
> **Ray Peat:** Yeah, the Mexican pharmacies manage to get it through the mail.
>
> **Patrick Timpone:** Yeah, you can get the SinoPlus there, right?
>
> **Ray Peat:** Mm-hmm.
>
> **Patrick Timpone:** Mm-hmm. Here's a question for Dr. Peat from Anna. When I have a sweet fruit like watermelon or honey on an empty stomach, after five or 10 minutes, I get a dull pain around the liver area and feel cold. I have a little fruit after food and I don't have this problem. Does this suggest I have a problem with fructose and should avoid fruits? Or can this be related to estrogen as my mom seems to have similar symptoms?

### Source 11 — Generative Energy #54: Top Three Hair Loss Supplements? | My DHT Experience | Is Iron Donation Healthy? | Raw Food

Danny Roddy · Interview · Apr 11, 2021 · https://app.podcastguru.io/podcast/1525148857/episode/54-top-three-hair-loss-supplements-my-dht-experience-is-iron-donation-healthy-raw-food-with-danny-roddy-62c84d6547c292b1e74e865e4f8598ba

> Get a little coffee break here. OK. Why would someone experience negative side effects such as anxiety, jitteriness, panic attacks as a result of NDT 4.5 micrograms of T3 and 19 micrograms of T4? So I think you could approach this a few different ways. So I don't know what brand the NDT is, but in my limited experience, every single brand of thyroid is slightly different. And I've talked to people that have used like one brand for a long period of time and they didn't think it was effective or they thought it was like too stimulating and they switched to another brand. It was like just completely different. So that's one possibility. The other one is this is such a tiny dose that again, if the product is everything that it's supposed to be, I would imagine this might be some kind of nutritional deficiency or something. So if I jump back into my notes program here. man we keep getting into references I'm spamming all the time but this one is from 1961 Harris and he says in general hyperthyroidism or like elevated thyroid function has been shown to increase the need for many dietary essentials whereas hypothyroidism appears to ameliorate some dietary deficiencies and then Ray Ray has a similar quote in 2016. He says, 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. So that was in response to somebody that was having an adrenaline, anxiety, jitteriness, panic attack as the result of using thyroid. The last thing – so again, it's essential to get blood work as well when using thyroid. So I would never suggest somebody try thyroid without at least getting their total cholesterol measured because – and the reason I specifically say the cholesterol is – Not infrequently does a person have too low of cholesterol, like in the 120s or 30s. And taking thyroid in that situation would probably be dangerous because thyroid would lower the cholesterol further. And then the person, if cholesterol is like an adaptive substance, they're lowering it to a level that they can't adapt. I think that's where you get really bad situations like suicide and seriously bad depression and things like that.

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