How much T3 converts from taking T4?
Now this maybe a "how long is a piece of string question" but if someone is a reasonable converting of T4 to T3 then if one takes 100mcg. of T4 what percentage of the T4 converts to T3?
Any ideas, or am I asking a totally unanswerable question.
I think the body makes about 2mcg T3 per hour (just what i have heard on the net, so not 100% fact). So we make T3 from the thyroid, but the majority of the T3 comes from conversion in the liver from the T4.
I don't know how much is converted, but the better your liver, the better your conversion. Women have more of a problem with this because oestrogen gets in the way of conversion. Hence high oestrogen is a big issue with thyroid and the reason why 9/10 people who have this illness are women.
Many thanks marsaday,
please see reply to Clutter.
In the pituitary, 80-90% of T4 is converted to T3 (4,148,149) while only about 30-50% of T4 in the peripheral tissue is converted to active T3 (149,150). This is due to the inefficiency of D1 and the presence of D3 in all tissues of the body except the pituitary that competes with D1 and converts T4 to reverse T3 (7).
the reason I am asking is because I am going to add some levo. to my 1.5 grains NDT.
I cannot raise the NDT any further with out getting overdose symptoms.
My T3 is at a good level but some hypo. symptoms have returned and my TSH has gone up hence the reason for thinking of adding levo.
I am trying to work out how much levo. to add and how much of that levo. would convert to T3 as I do not want my T3 to go over range.
Before starting NDT I was taking 100mcg. levo. and did the Genova 24 hour urine test which showed I was converting the T4 to T3 reasonably well but I was not taking enough of it. My G.P. would not increase because of low TSH so I decided to go onto NDT.
Results January 2017
TSH - 3.2 range 0.35 - 4.7
T4 - 6.8 range 7.8 - 21.0
T3 - 5.1 range 3.8 - 6.0
Previous results July, 2016
T3 5.2 All same range as above.
Any thoughts on how much levo. I should add.
Adding T4 will raise FT3. It's suck it and see to how much 12.5 or 25mcg will raise FT3. If FT3 goes over range you can adjust NDT or T4 dose.
Why didn't you just get some more T4 and increase yourself. Then add in a little T3 to top up if needed.
Yes I wish I had done that now but kept reading how marvellous NDT is so thought I would give it a try.
I had a difficult time raising the NDT even to 1.5 grains so I am worried I will have a bad time if I changed back to levo. and T3
NDT is over rated and it is such a shame most forums are so pro NTH. I think the problem with conventional T4 treatment for many patients who use forums and then get onto NTH is that higher doses of T4 are not tried first and T3 is not then tried in various ratios with the T4.
They move over to NTH and a lot still experience the same issues. I am not saying NTH are better or worse, and they do work well for many people.
It would be an interesting world if the standard protocol the world over was to use NTH to treat thyroid issues. I am sure we would still have thyroid forums trying to help people feel better.
The issue i see with NTH is the ratio of T4 to T3 is set, so it is hard to work out your own ratio mix. T4/T3 allows this much more easily. People who are converting well probably need less T3 than the normal 4:1 ratio. I think you may be one of these people.
Dr Ken Blanchard in the USA advocates using a T4 to T3 ratio of 98:2. This is basically a tiny amount of T3 in most peoples mix. This type of protocol is totally over looked by docs and forums alike. He has a book out on amazon and it is a great and simple read.
I don't think you would have any problems going back to T4/T3. I would try 100 T4 again with a 1/8 dose of T3 = 3mg approx if using a 25mcg tablet. If your FT4 was 7 on 100 T4 i think you really needed to try more T4 before any T3 was introduced.
Without wanting to agree or disagree with you, one question springs to mind:
If it were that simple (that is, take mainly T4 drugs, and add about 2% T3 if you don't feel optimally treated on T4 only), then why do so many people on T4 only drugs have very low FT3 levels, sometimes even below range levels...? I have not read Dr. Blanchard's book so I have no idea what he says about that (if he raises it at all), but I'd be interested to know as I never seemed able to get my FT3 levels up where they should be, no matter how much T4 I took.
Yes but this low dose of T3 wouldn't suit you would it. The poster has good levels of T3, or goodish, hence why i think this particular protocol MIGHT work for her.
Remember i am not saying a low T3 to T4 ratio will suit everyone. It is a particular style of thyroid treatment, the same as the NTH style or T4 only style or T3 only style. It is a style which really gets zero attention. I stumbled on this way of treatment myself after many years of upping and lowering and T3 only and NTH and etc etc. It works for my body and i convert very well.
I don't know if all Dr Blanchards patients do well on a little T3, but this is what he is saying. I find it hard to believe myself. The key difference he has (and he talks about it) is the fact the T3 is especially made for his patients and is SLOW RELEASE. I think this makes a huge difference to people. We can't get it here in Europe, but his particular patients can at his practise it seems.
I see, interesting...thanks for the clarification!
For some of us, there is without doubt something fundamentally different about the T4/T3 route versus desiccated thyroid. I wish I had any understanding of what makes it so different, but I don't. What I do know is from personal experience... I tried many brands of levothyroxine and reacted badly to all of them regardless of dose. Well, I say regardless of dose, but actually, the more T4 I took, the worse I felt. Adding T3 in any ratios did not work either. I tried for a long time before resorting to desiccated thyroid.
NTH works really well for you and many others, no doubt. But there are also a large number of people who it doesn't make any difference for and people go on it and struggle just as much as T4 only.
I would like to see better thyroid info given out on the forums explaining the ins and outs of all treatments, rather than just suggesting NTH will get you well.
Who do you think should be giving out this 'better thyroid info'?
The forums (e.g. thyroid UK) could produce an over view of the different protocols, pointing out the benefits and drawbacks of treatments. They could also specify what to look for when looking at blood tests and where one protocol might be more efficient for a certain profile. Eg, patients who have had a thyroid removed do best on NTH.
Also guidance on how you can compare treatments. Many times T4 only patients are encouraged to try NTH and they find improvements BUT they never tried the addition of T3 and so the comparison with T4 only is unbalanced. Patients then have to fight to get NTH or pay a lot for it on the net. Yes T3 is now also a fight to get, but it is much cheaper than NTH (depending on the amounts you take i suppose).
T3 is far more expensive in the UK than desiccated thyroid - despite being a licensed product here. (Based on last price I saw, T3 is about nine Great Britain Pounds per 25 microgram tablet.)
Yes but that is due to the way the nhs doesn't function properly. If enough people can force the issue it will make the headlines the same way hydrocortisone was being sold for far too much. T3 is cheap to produce and costs much less than nth on the net.
The other thing is how many docs will prescribe t3 over nth even though as you say it is currently more expensive than nth. I reckon it is still harder to get nth than t3.
But that is how it is - in the UK.
I know my chemist told me recently nearly £300 for 100 20mcg tabs. Crazy! Apparently went up from something like £30 per 100. And a newspaper article highlighted how it seems to be only in the UK where the price has been hiked up to this extent. Why?
Why exactly, only 2 euros for a months supply over the counter in Greece.
Thyroid UK have a website with info on, but the forum is meant to be for patients to share experiences and ideas. Your idea sounds very idealistic, but I don't see it happening. And if it did, you can be sure it would very quickly be exploited for profitable gain.
Plus, many people actually need to be told what to do every step of the way... brain fogged patients can't easily make sense of all this stuff. It's very complicated and often very hit and miss.
At least here on this forum there are some very knowledgeable regular posters who keep the flag flying for us all - like diogenes
When my T4 was around 7 it was when on 1.5 grains NDT not 100mcg. levo.
All results shown above are when on 1.5 grains NDT.
Sorry if I have caused any confusion.
When on levo. T4 and T3 were usually around mid range, once T4 rose to 19 it was then I felt quite well.
Right so this info is very useful. You were actually feeling okish on 100 T4 and the Ft4 was at 19. So the next step would be to see how more T4 worked out. It is useful to try get the FT4 into the 20's and possibly over range. If you start to feel no better on a T4 increase this is the point where we can say more T4 is not having an effect and will actually be working against you. TSH will be more suppressed and T4 to T3 conversion will be lowered, plus more Rt3 may be produced.
BUT if you felt even better on say 150 with a FT4 of 24 then this would be a good sign. If you still needed to tweak things this may be where you introduce a low amount of T3
Thank you for your reply,
I was taking 125mcg. levo. when T4 went up to 19, this is when all my nutrients were optimal. G.P. then reduced to 100mcg. because of low TSH and on 100mcg. levo. T4 dropped to 14.
It was when taking 100mcg. levo.I decided to do the Genova urine test and it showed I was converting reasonably well but I was just not taking enough of it.
In hindsight I should have purchased more levo. tried that and then add T3 as you suggested before trying NDT.
me again, I have recently ordered more NDT so I may try and add in levo. to NDT. and then gradually increase levo. and reduce NDT, and eventually get back to levo. and if need be add in T3.
Do you know of anyone who has done this?
I tried something along those lines. (hope it's ok to butt in here ). I still couldn't tolerate the levothyroxine. As soon as I got to 25mcg thyroxine things were awful (regardless of NDT dose) Am more tolerant of NDT + T3.
Thanks Gingerbread, of course it's O.K. to chip in.
I just cannot raise NDT any further with getting a reaction. I think there is too much T3 in it for me so thought I would add T4 instead.
Give it a go, fingers crossed it works. Everything is worth trying in the quest for the perfect thyroid medication regime that gives us our full lives back!
1 1/2 grains = 54 t4 and 13.5 t3. You are someone who possibly wants to be on around 5mcg t3 per day. So even on the smallish nth dose you are taking too much t3. Obviously I can't say for sure so it has to be a case of trial and error. I would try using 1/2 grain plus 75 t4 and see how you get on. A straight swap will be fine. I used to take 5 grains and just switched over to 150 t4 and 50 t3
Thank you, did you feel O.K. when you initially changed over?
No difference between the two. T4, nth, t4/t3 all performed the same for me. The key was getting the right mix.
Glad you have found the right mix.
Many thanks marsaday for all you advice.
I think marsaday you have hit the nail on the head - we are all different and need different things. Some people react to other substances/compounds in the make up of meds. There is a myriad of reasons we need different options, Our 'deficiency' is not necessarily going to be the same as the next person, and our ability to convert t4 to t3 no doubt can vary for many reason. And if there is something impacting on uptake that can effect our needs.
The problem being that the medics will generally ignore all this and tell us we only need t4!
They ignore the fact that other connected issues can have a great effect on our initial thyroid problem. E.G Adrenal disfunction. What I can never figure out is why? Why they choose to ignore the possibilities and why they cannot give patients both the benefit of the their doubt...i.e. consider that the patient might actually be right! And, give the patient the credit of the intelligence to know, as they are the ones experiencing the problem, only they can describe and know how it affects them.
One pill does not fit all.
Unfortunately, this has left so many of us looking for alternative help, we are flaying about in the dark trying to find something 'out there' that works for us. Then trying, with what limited information we have, to balance these complicated systems. When you consider the years of training Dr's and Specialists go through, yet this is what we 'untrained' people are having to do. Because THEY refuse to help us. They refuse to accept that medicine is only as up to date as what they currently know. Surely we can't all be depressive hypochondriacs? All with varying degrees of the very very same problems. What a very sad state of affairs! The future of medicine is not looking bright!
I myself am on t3 only, having found, having had t4 for over 20 yrs, that it was doing me no good (had been telling Drs that for the full 20 yrs) Blood was becoming toxic with it, caused all sorts of pains. Switched to t3/t4...helped for a while but pains persisted. Things worsened again. Adrenals were compromised. Every time stopped t4 pains went, every time reintroduced t4 came back. Now on t3 only. Much better, for a long time. Pains came back recently but Chemist actually changed brand - gone again. Must be something in make up of tabs themselves that build up and interfere? Adrenals still causing some issues but working on that.
I'm now worrying about when the surgery will decide, like it sounds, so many others are doing, to stop issuing t3. So precarious!
How come so many Dr's are able to mistreat so many people and get away with it? In any other occupation you would probably be sued or at least fired for such failings! Coming form a teaching environment, if a teacher was 'failing' children's education the way these Dr's are failing patients, they would be out of a job, and out of the profession!
Yes all true. Doctors are very powerful people. They are bright, go to uni, learn what previous docs were taught and go out and practise. Medical protocols change pretty slowly it seems.
These docs are so busy they have no time to learn new stuff. The forums are stuffed full of people commenting that their GP knew nothing about x or y.
I think the area where new research and education should be taking place is in the governing bodies for these illnesses. So the British thyroid assoc. should be responsible for doing research into the huge thyroid area. They would then pass on new educational practises. Thats how i see it working in the UK, but it obviously isn't working. Some forums have been banging on the door of the BTA, but they just won't listen or enter dialogue.
I am thinking they have a lot to hide and so don't want to engage because it would be bit like the tobacco industry confronting its lies it told for decades.
If you think about it, some progress is being made. Our TSH range is now down to 4 when it used to be 10 in the 1990's (maybe early 2000's). I know docs still don't like to treat until the TSH gets over 10, but we do have a new tighter range.
Think about this small anecdote which sort of reflects how the medical world works. In the early days of medicine (not sure of date but 1800's or early 1900's) a doc noticed many women were dying after childbirth.
He decided to wash his hands after treating a patient or before attending a birth. The death rate dropped big time. So he wrote a paper which was ridiculed by the medical establishment and the guy was put in his place.
This seems to be the way these super brains work. They know everything, the info they learn takes a long time to understand and so i think they are unhappy when new ideas contradict the status quo. They see it as a personal failing.
Technology is going to have a positive impact on this type of group think. Technology and algorithms are going to do more of the thinking in the future and so will be unbiased. They will be able to see the data in front of them and provide the correct solution.
THE SEMMELWEIS REFLEX
The Semmelweis reflex or “Semmelweis effect” is a metaphor for the reflex-like tendency to reject new evidence or new knowledge because it contradicts established norms, beliefs or paradigms.
One of numerous accounts of Ignaz Semmelweiss may be found here:
The words "it varies" are vital here!
Have a look at this paper if you want to understand a lot more:
Nevertheless, there is good agreement that about 1/3 of T4 daily produced (~130 nmol) in normal humans is converted to T3, which corresponds to about 40 nmol and thus 80% of the estimated total daily T3 production of 50 nmol.
What happens to the rest? The link explains that:
40% of T4 is converted to rT3
20% of T4 is excreted in faeces
Many thanks, I will have a read of the link.
It isn't easy going - but is worth at least a go.
Thank you every one for all your replies.
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