Sorry to have to bring this thread back from the dead, but:
I’ve found a study from March 2013 which implies that it is T3 – not T4 – which the hypothalamic-pituitary axis senses, and which lowers TSH levels.
I can’t say that I completely parse out what that article is saying but I do not read that as saying that elevated plasma T3 will feedback and suppress TRF and TSH like T4 does (by way of local conversion in the mediobasal hypothalamus by D2 into localized elevated active T3). It seems to be saying that without astrocyte specific D2 plasma T3 is still normal because other cells step up D2 production in the face of elevated T4.
The basic concept is still as stated
The point was
Again, not an endocrinologist.
That’s odd, because in the Introduction to that study, they state:
Local conversion of T4 to T3 by cells in the region of the brain, not elsewhere impacting plasma levels.
Like politics the T3 levels that matter are local, and regulated by local levels of deiodinases activiating T4 and deactivating T3. Most of the body’s T3 is produced outside of the thyroid by D2 conversion of T4 into T3. D2 is mostly regulated by a feedback of local T3 levels (more local T3 downregulates it) and T4 induced ubiquitination.
Again, the cross talk that goes on between these deiodinases and other regulatory enzymes at tissue specific locations varies according to site and I cannot claim to have a very solid grip on the complexity of the systems and the levels of feedback. I undertstand just enough to understand that I understand only a small portion of how it works and to be skeptical of simplistic explanations, especially by self-appointed experts.
Again, my limited understanding is that T4 invokes an additional level of localized regulation and feedback control above that imparted by a T3 approach which to my read means less risk of adverse outcome.
FWIW and no more than that.
UPDATE: I think I’ve found the smoking gun!
First, there’s this passage from Molecular Basis of Thyroid Hormone Action, page 93:
(Figure 23 is on the next page, and shows 6 pretty graphs.)
Then, there’s this study from the 1977 Journal of Clinical Investigation, pp. 1230-1239, whose abstract contains this little gem:
Both of these are based on animal studies, but if humans behave like the rest of class mammalia, it appears that the T3 Receptors have 1000 times as much affinity for T3 as they do for Reverse T3. In other words, it reqires a T3-to-rT3 ratio of 0.001 or lower (i.e. 1000 times as much rT3 as T3) before the number of receptors binding to T3 is cut in half.
And normal blood concentrations of total T3 are 2-18 times HIGHER than blood concentrations of Reverse T3.
So even if Reverse T3 is a T3 antagonist, it’s a pretty darned weak one.
A lot of information is available on this subject that may not have been in the past, so I’m going to add some here for you. High RT3 can be problematic.
http://press.endocrine.org/doi/abs/10.1210/jcem-41-6-1043
More info on studies you can look into:
Reverse T3 Suppresses T4 to T3 Conversion
Endocrinology 101(2):453-63
A study of extrathyroidal conversion of thyroxine (T4)to 3,3’,5-triiodothyronine (T3) in vitro
Chopra IJ
Most endocrinologists believe that reverse T3 (rT3) is just and inactive metabolite with no physiologic effect, which is not the case, however. This study and subsequent others demonstrate that rT3 is a more potent inhibitor of T4 to T3 conversion than PTU (propylthiouracil), which is a medication used to decrease thyroid function in hyperthyroidism. In fact, rT3 is 100 times more potent than PTU at reducing T4 to T3 conversion. Clearly, rT3 not just an inactive metabolite. The authors conclude, “Reverse t3 appeared to inhibit the conversion of t4 to T3 with a potency which is about 100 times more than PTU…”
Brief Report
The Journal of Clinical Endocrinology & Metabolism; 91(1):225–227
Thyrotropin Suppression by Metformin
Robert A. Vigersky, Amy Filmore-Nassar, and Allan R. Glass Endocrinology Service, Walter Reed Army Medical Center, Washington, DC 20307
This study noted that patients on metformin (Glucohage) had a subsequent suppression in TSH level without a change in serum thyroid levels, demonstrating that there is often associated a thyroid resistance in patients with insulin resistance that is partially improved with metformin. This study adds to the mounting evidence that due to a variety of factors, including tissue altered metabolism of thyroid and thyroid hormone resistance, standard thyroid function tests do not correlate with tissue effect of thyroid.
Additional Studies
Low normal thyroid levels result in a higher risk of heart disease than if you have high cholesterol, high blood pressure, if you smoke or even have diabetes. Individuals with low normal thyroid levels are 2.5 times more likely to suffer a heart attack. This is greater than if you have high cholesterol (2.4 times risk), high blood pressure (1.6 times risk), if you smoke (2 times risk) or have diabetes (2.4 times risk). Doctors and patients are well aware of these risk factors for heart disease but fail to correct the more important low normal thyroid levels. Many patients needlessly suffer heart attacks because their physician tells them their thyroid is fine because it is in the normal range instead of optimizing to more optimal levels.
Risk Factor Age Adjusted Relative Risk
Low normal thyroid
Hypercholesterolemia
Hypertension
Smoking
Diabetes Mellitus 2.5
2.4
1.6
2.0
2.4
Annals of Internal Med, 2000
.
Many physicians have realized that patients can be profoundly hypothyroid and still have normal values of TSH and Free T4. In the British Medical Journal several physicians noted this by stating, “We wish to question present medical practice, which considers abnormal serum concentrations of free thyroxin and thyroid stimulation hormone-those outside the 95% reference interval-to indicate hypothyroidism but incorrectly considers “normal” free thyroxin and thyroid stimulation hormone concentrations to negate this diagnosis. It is unusual for doctors to start thyroxin replacement in clinically hypothyroid but biochemical euthyroid patients.” They note that of 80 patients who were diagnosed as hypothyroid on established clinical (signs and symptoms), only 5 patients had abnormally low T4 levels and only 4 had abnormal high TSH levels. The averaged TSH concentration was below the middle of the reference range. They state that these people deserve treatment otherwise they are condemned to many years of hypothyroidism with its complications and poor quality of life.
British Medical Journal
.
In a published article in the British Medical Journal, the authors state, “For over 80 years, before the advent of TSH testing, physicians with outstanding ability have regularly treated thyroid patients with enough thyroid to clinically normalize their patients regardless of dose. The maxim of the day before TSH arrived was to give enough thyroid until the patient felt better. Medical students are still repeatedly told to treat the patient and not the lab values, but this quickly gets forgotten and disregarded when it comes to thyroid. The 80 years of experience with thyroid hormone treatment demonstrated that people would normally need 200-400 micrograms of T4, such as Synthroid, or 3 to 5 grains of desiccated thyroid. The long-term studies of over 40 years show no side effects from such doses and thyroid is probably the safest long-term drug of the Century. When TSH testing came into use in 1973, the average doses dropped to 1/3 of the doses previously used.”
British Medical Journal
.
4. In a study published in the Journal of Endocrinology and Metabolism, clinical signs were compared to blood tests. The authors demonstrated that individuals have varying degrees of thyroid resistance in different tissues. The authors describe this as a metabolic hypothyroidism in different tissues. They state “…tissue hypothyroidism at the peripheral target organs must be different in the individual patient.” The authors summarize their findings by stating that they agree with the statement in an endocrinology text book stating, “The ultimate test of whether a patient is experiencing the effects of too much or to little thyroid hormone is not the measurement of hormone concentration in the blood but the effect of thyroid hormones on the peripheral tissues”
The Journal of Clinical Endocrinology & Metabolism
Basic and clinical endocrinology, 3rd ed. London: Appleton
.
Low thyroid is associated with an increased risk of coronary artery disease, heart attack, heart enlargement, stroke, infections, and cancer.
Numerous studies
.
In a study published in the Journal of Clinical Endocrinology and Metabolism, it was shown that T4 preparations such a Levoxyl and Synthroid resulted in very minimal increase in metabolism while supplementation with T3 was shown to increase metabolism by an average of 18%. For a person consuming a 2000 calorie diet, 18% is equivalent to burning an extra 360 calories per day. Thus giving T3 would equate to approximately a 40 pound weight loss in a year. This is equivalent to approximately jogging on a treadmill for 1 hour per day. If we would simply optimize everyone’s thyroid, we would no longer have the obesity crises in this country. This could easily be remedied and drastically cut he incidence of diabetes, heart disease, hypertension, stroke and cancer. Thyroid should never be given as a weight loss medication but appropriate replacement with the proper preparations often elevates a number of symptoms, often including continued weight gain.
The Journal of Clinical Endocrinology & Metabolism
.
Reverse T3 blocks T3 action and lowers metabolism
Research Experimental Medicine
.
Thyroid hormones improve blood flow to heart and prevent heart attacks
Thyroid
.
There is an increased risk of arrhythmias if your T3 levels are low and/or your reverse T3 levels are high. This is opposite of what most doctors think.
Journal of Cardiology
.
Flame retardants are building up in people’s bodies and blocking the thyroid effect resulting in a diminished thyroid effect despite having normal thyroid levels.
Toxilogical Sciences
.
Organochlorine compounds (pesticides) are well known to alter the thyroid hormone system by decreasing serum thyroid hormone levels in several species including humans.
Environmental Health Perspectives
.
The higher the level of polychlorinated biphenyls (PCB’s) in children the lower the thyroid and the higher the level of cadmium in children the lower the thyroid levels (not picked up on standard blood test)
Environmental Health Perspectives
.
“In an ambitious review of the literature from laboratory experiments, wildlife observations and human epidemiology, Françoise Brucker-Davis concludes that wildlife data clearly demonstrate thyroid disruption by synthetic chemicals.”
Thyroid
.
“Synthetic chemicals are released into the environment by design (pesticides) or as a result of industrial activity. It is well known that natural environmental chemicals can cause goiter or thyroid imbalance. However, the effects of synthetic chemicals on thyroid function have received little attention.”
Thyroid
Some explanation about RT3 hormoneandlongevitycenter.com - This website is for sale! - hormoneandlongevitycenter Resources and Information.
Help from doctors who understand RT3
Reported.
Aww…c’mon. It’s interesting when new posters educate the board. Re-reading this thread after a long time, what were we posters talking about? It’s not like any of us had any knowledge about the topic.
I might add that I’ve actually had papers in some of those journals he/she links to. Yeah me!!!
Hi Dewey, why have you reported me?
There’s a lot of new information out there, and as well - studies are emerging - even just this year or last year – more studies.
The whole thyroid issue is such a huge one, especially when so many of us are struggling to get the right help.
I have an elderly endocrinologist who has “seen it all” so to speak and even he told me that it isn’t “study based” but that if I wanted to get my hashimoto’s into remission that I needed to quit gluten. He told me that TPOab can be lowered by taking selenium and a tiny amount of zinc - but that I have to be very careful with these amounts. He’s a “top doc” for a reason. Yet he’s near retirement, and when going to a new young endocrinologist she had “no idea” that selenium can help lower TPO ab, or that quitting gluten is part of the equation. You see, the doctors need to stay on top and catch up with the emerging information. There are numerous MD’s that are staying on top of it; Amy Meyers MD is an example of a physician who herself battled graves disease and now has no thyroid; she is on the cutting edge of thyroid info.
One fascinating study out of Italy shows the use of Wobenzym in conjunction with levothyroxine to actually effectively and factually lower TPOab in patients with hashimoto’s. The dosing was rigorous yet highly effective. Yet, even with this new study; our current physicians (any that I’ve talked with) are completely unaware of this new study. Here’s the information on that study (posting in a moment) if someone has full access they can read the entire study. But anyway, I’m not sure why I’m being reported when I was researching the subject of RT3 because I’m considering taking T3 and I needed to research - I’m someone who likes to get to the bottom of things and read the studies if I can find them… So there’s a ton of new info to share.
THank you.
EFFICACY OF A FOOD SUPPLEMENT
IN PATIENTS WITH HASHIMOTO THYROIDITIS
M. NORDIO and S. BASCIANI
JBRHA Vol 29, No 1, January - March, 2015
Abstract:
Thyroid inflammation has been commonly seen in recent decades, due to a series of factors and is
considered as the most frequent thyroid illness. It is characterized by some distinctive traits, which include
morphological and hormonal modifications, often in association with an elevated anti-thyroid autoantibody
title. The aim of the therapy is to improve symptoms as fast as possible, treating inflammation and subsequent
hypothyroidism, when present. Therefore, we evaluated the efficacy of a Food Supplement (FS) containing
enzymes which is commonly used in various inflammatory processes and is able to modulate immune
reactions during inflammation in a very rapid and efficacious way. An open, controlled study was then
designed and 45 patients with Hashimoto thyroiditis were enrolled and divided into 3 groups (FS alone;
thyroid hormones alone; FS plus thyroid hormones). Blood, morphological and subjective parameters
were considered. The results obtained indicate that the FS used in our study is efficacious and safe when
used alone and/or in combination with thyroid hormones in the treatment of autoimmune thyroiditis, as
documented by the improvement of the majority of the parameters considered. The efficacy was considered
faster than thyroid hormones alone as far as subjective symptomatology is considered. In conclusion, the
use of the food supplement evaluated herein during inflammation may be considered an additional tool in
clinicians’ hands, when facing patients with autoimmune thyroiditis, especially in presence of subjective
symptomatology, in order to rapidly alleviate it.
EFFICACY OF A FOOD SUPPLEMENT
IN PATIENTS WITH HASHIMOTO THYROIDITIS
M. NORDIO and S. BASCIANI
JBRHA Vol 29, No 1, January - March, 2015
Hi Dasmoocher, I’m not sure why Dewey reported me. I found out in 2013 that I have hashimoto’s. I was a long-distance swimmer (for fun) and had just completed a “race walking” event; but I was exhausted, and having huge trouble, even though I mainly ate only whole foods and was very fit. It was the strangest thing; and then a lump emerged within my throat; my thyroid started swelling. It has been a long journey to wellness for me. I have seen an endocrinologist for these three years and I have researched and researched and researched. He at first had me on synthroid; which possibly nearly killed me, then tirosint, he had to take me off of these medicines immediately due to the dangerous reactions my body had. He very reluctantly put me on NDT, armour thyroid, on a very small dosage, and bit by bit increased it according to the prescribing information and it has been a long journey back to wellness. Back in 2013, for many, many months - I could hardly get up off the couch/chair, could hardly stand long to wash my dishes; I was very hashimoto’s ill. At one point my thyroid swelled so large that when it had gone back down in size the next morning, I literally heard cartiledge make a “popping sound.” I am someone who is on a serious journey back to wellness as MANY people have actually gotten this hashimoto’s in remission, I aim to be one of them! I am thrilled that I have my life back, I take NP thyroid (better than armour) and I avoid all gluten, and for some reason cow milk makes my thyroid swell. I got help from a dietician and got a blood test for sensitivities, my endocrinologist looked at it and understood that there were reasons for an allergic reaction to the synthetic thyroid hormone for me. I have had to do a TON of the legwork and research myself. For some reason, I had to learn myself that splitting my dose and taking it sublingually would help me to feel better – then I asked my endo, THEN he agreed, yes, that would help, because the T3 lasts about 3 hours so if I did that I would get it split throughout the day… (the T3 I speak of is inside of my NP Thyroid which contains both T4 and T3 and is believed to also contain a small amount of T2 and T1 as well, naturally occurring.) ANyway - it’s been a huge and long journey. I am GRATEFUL for Isabella Wentz’s journey ahead of mine - she is a pharmacist who went through this journey, studies the studies herself, tried numerous things (like me) and got herself well. She got her hashimoto’s into remission. Then there’s books like Stop the THyroid Madness, these people are trying to help us get into “optimum range” not just into “range.” So much information here but I’m on a journey and I’m finding out that I have to do a TON of the leg work myself. My doctor (endo) doesn’t just come out and tell me the “whole story” on how to feel better – I have to research and then ASK the questions. Thankfully, I’m learning what questions to ask along the way. One of my most recent is… IS Rt3 and antagonist against T3? You see, I want to know the truth, not just what a bunch of old ladies or whackos are saying – I want to know what the studies say - I want to know the truth - because I don’t want to make a mistake and injur my health, I want to do the right thing. IT is quite amazing what a patient has to do to try to get well instead of just accepting the idea that my body will take it’s course of killing my thyroid. During this journey, when I was at my worse, I would say that hashsimoto’s felt like wearing a “suit of fatigue” somehow close to how mono feels, and my legs felt heavy, the lights were too bright, the sound was too loud, I was utterly exhausted… Well now – my endo has helped me so much, and then I myself have done the things nutrition-wise through research and more to help myself - and my endo has taken these into his consideration as well… Why do I have to work so hard to get the right info? Our modern endocrinologists need to be brought up to speed. I should have been told to quit gluten, cow milk and soy from the start. I should have been told to take NDT and split my dose and take it twice in the day. I should have had someone working not just to get me in range, but to get me “optimum.” Someone should have been checking to see if my RT3 was in the improper range or optimum range, basically someone should have been making sure that I was converting my T4 to T3 well and that I had an appropriate “optimum” range of T3 - to ensure that it wasn’t being blocked – so that I didn’t have to feel similar to having mono. NOW – I FEEL GREAT. Yeah, I still have to stay on top of taking my thyroid hormone - I can live with that. I may not be able to handle intense fitness yet without going backwards – but I am only feeling better and better and the journey here is long and hard and we need MD’s who KNOW THE JOURNEY.
Moderator Note
A lot of times when we have new posters who link to articles like this it’s just someone spamming their own articles. For anything questionable like this, we prefer that our members just report it and let us moderators figure out if it’s actually a problem or not, so don’t take the post report personally.
In any event, this doesn’t appear to be a spam and it’s adding helpful information to the thread, so thank you for posting it.
Welcome to the SDMB and we hope that you enjoy your time here. 
This bit seemed spammy.
Yep, that bit does seem spammy, and I would definitely take the testimonials there with a huge grain of salt.
Our new poster doesn’t seem to have signed up just to post that link though, so I think we’re good.
You did the right thing in reporting it.
Would you like me to remove that part? I can do that. I posted that part for a couple of reasons - one is because they’re MD’s who are addressing RT3 – like - finding the MD’s who will do that is like finding a diamond in a haystack (I don’t mean whacko scarry docs who prescribe dangerously) – and the other reason is because there are SO MANY people who are so exhausted with these thyroid problems and their doctors are checking their TSH and telling them there’s “normal” yet the folks feel horrible - so like - when I see a place like “Hotlorf Clinic” I think - there’s the answer… And like if I had never gotten better - if I were still suffering, I’d consider it as a place to fly to in the future – I can’t accept fatigue as a way of life. THere’s more than the Hotlorf Clinic out there - but there are also a ton of quacks and sorry to say it but - chiropractors out there claiming to have the answers for hashsimoto’s and thyroid problems; they’re claiming to be some sort of chiropractic endocrinologist (something like that); people who are charging thousands and QUACKY. So I’m someone who wants real answers, I want to know the truth. Along my journey I’ve also seen a statement that I have NEVER been able to verify - and the guy who makes it sells iodine… The statement is that bromide and chloride replace iodine in the receptors of the thyroid… Um… True or Untrue? I have never been able to figure it out so I won’t believe it. Yet my question, if it’s true, it could mean that all the swimming was part of what triggered my genetic predisposition to thyroid problems… to trigger the hashimoto’s portion of it… And - if it’s true, it could mean that iodine could be the answer - yet that is highly controversial, some say that iodine plus hashimoto’s is like igniting a fire… And the consequences are such misery I’m afraid to go there. I’m afraid to give that a try… Is it truth or quackery? Never found the answer. Anyway, thanks for listening – I hope that if any of you find any worthy concrete studies on T3 and RT3 that can help me – it would be much appreciated. Coming from someone who used to look at people with thyroid problems and think that those people needed to get up off the couch, exercise, drink more water and eat right… Wow, did I have a lot to learn! As for me - onward and upward - feeling better and fighting to win! Working to get my TPO ab in range… Formerly it was in the 900’s… (in 2013) this year it’s been down in the upper 200’s… I’m very very very careful almost all the time with everything I eat… Taking my NP Thyroid (which is better than armour by far!)
Last I knew, this Quackwatch was rather quacky itself; while it might do a good job in some regard, it has also reported someone as a quack who isn’t one… And last time I did some research on Quackwatch it was… Get this… One person doing all the deciding on what is quacky and what is not… Not sure where that stands these days… Maybe there are two of them now? Maybe it’s still just one? Probably helpful at times, but even quackwatch needs to be quack-checked.
Thank you so much!!
I found your site when I was trying to investigate RT3 and find information on studies etc. on the matter. I found you because i have to do the legwork myself to find out what is true and what is not; because many of the endocrinologists sadly are locked into just checking TSH etc., they don’t really know how to make us well – some, like one of mine, know some of the journey to wellness - but not the entire journey - he wants to raise my T4 even though a study just came out that shows that elevated levels of T4 are linked with sudden cardiac arrest. Another endocrinologist that I tried ( a younger one) knew nothing of how selenium lowers antibodies (the old endo knew that and told me early on) and she didn’t know that I needed to stop gluten to help get this into remission while the old endo told me that - even though he said that the info is not study based, that there seems to be a correlation) – Ugh. So onward I search; not just trusting the words being spoken - but searching searching searching and then to NCBI I go to search for the studies… Anyway, I found your site along the journey. Thank you.