Thyroid UK
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T3, T4 whats the difference please? In UK and on levo, which is okayish, would I benefit from both or is one better than other?

If I would benefit from being on both and we are only prescribed levo where would I get the other and how would I know what and how much to take , I realise they are better in conjunction and also what are the benefits? overall.

All this is ongoing and learning curb been on levo 4 yrs, its helps a little but nowhere near as much as I would have thought, and I tend to crash one moment and get back on track the next, its a fine balancing act, it would be wonderful to be balanced and back to me, I have a serious liver, lung condition too which is inherited genetic disorder and why I suspect I ended up with hashimotot's thryoid, so all answers welcome from this learner, I would like to know to what the European standards are with regards thryoid and what they put patients on and how more effective it is , say in Greece, Spain...etc. Many thanks! I currently take 100mcg, and have done for these past few years although they dropped me down to 75 and of course the weight which is the main bug bear with me creept on almost immediately, keeping my weight under control on 100 seems to be the only thing I can do.

6 Replies

From my own personal point of view I believe that adding T3 to T4 is more beneficial. You get the direct Active Hormone (T3) more quickly than converting it from T4.

I know in Greece T3 is rarely prescribed but it is available over the counter. T4 or T3 is non-prescribed.

Someone who has knowledge of where to source T3 will send you a Private Message.


Flo1, If you have low TSH, high (in range) FT4 and low FT3 you will benefit from the addition of a little T3. If you post your recent thyroid results and ranges (figures in brackets after results) members will advise whether you are optimally medicated. Undermedication is the most common reason patients on Levothyroxine don't do well.

100% gluten-free diet can reduce Hashi flares, symptoms and antibodies.


I am not a medical professional and this information is not intended to be a substitute for medical guidance from your own doctor. Please check with your personal physician before applying any of these suggestions.

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will do, I will get the last results today ..many thank you's


The thyroid gland makes both T4 and T3. Mainly T4, which is, basically, the storage hormone, and is converted to T3 in the body.

T3 is the active hormone, which is needed by every single cell in your body. When there's not enough T3 to go round, you can get all sorts of problems, anywhere in the body. But, the main four symptoms, that everyone associates with low thyroid, are :

Weight gain, and difficulty losing it




However, the difficult thing about thyroid symptoms is that they are none specific. Not every one has all those four. Some people may just have stomach upsets, say, or bags Under the eyes. There are over 300 possible symptoms, but all of them could be caused by 'something else'. However, when you have a bunch of them together, they are more than likely caused by low T3. Doctors, however, know nothing about symptoms, because they Don't 'do' them in med school.

The treatment-of-choice in most countries (chosen by doctors, not patients) is Levo, or some other brand-name of T4. They assume that everyone is capable of perfect conversion. This is just not true. Lots of people have trouble converting - especially those with Hashi's. Other reasons for bad conversion are low cortisol, low nutrients, and the DIO2 gene defect. But your average doctor, world-wide, knows absolutely nothing about any of those. You have to come on a forum like this to find out about them!

If you have difficulty converting, then, yes, adding some T3 will make the world of difference. Even if you're a good converter, it would be more natural to have some along with your T4, because that's what the gland would naturally make. But doctors do not understand this. They are terrified of T3! They think it's going to give you strokes, heart-failure and osteoporosis - which is absolutely ludicrous, and you would think they should know better. But they Don't.

There's a school of thought which says that NDT is better (Natural Desicated Thyroid, made from pig thyroids) because it contains both T4 and T3 and is 'natural'. Quite how natural it really is, is debatable, but some people do much better on it. However, despite what the fans say, it is not for everyone. Some people actually do better on synthetic T4 and T3 - or even T3 alone. Some even do remarkably well on T4 alone. We're all different, and the trick is finding which one - and at which dose - is right for you. But, you're not going to be able to do that Under the 'care' of most doctors!

As for what happens world-wide, as I said, they all believe that synthetic T4 is the best (when they Don't have to take it themselves!). But, you're more likely to get NDT prescribed in the US, I believe. In the UK, doctors Don't know what it is and Don't care to find out. In the rest of Europe - apart from Belgium - it's either illegal or unavailable.

I Don't know what the T3 situation is in the US, but in the UK, it's so very, very expensive that doctors - who Don't know anything about it, anyway - are reluctant to prescribe it. In France and Belgium, you can usually get it from the doctor quite easily. But, it's still prescription only, as it is in most European countries, except for Greece/Crete, where you can buy it over the counter.

And that's the extent of my knowledge on the subject! :) Hope that answers most of your questions.

So, why did they drop your dose? Was your TSH Under-range? They are so ignorant! Once you are on thyroid hormone replacement, the TSH is of limited use, and certainly should not be used to dose by. The FT4 and FT3 should also be tested. However, ignorance is rife, and money rules in the NHS, and they usually refuse to test the most important one : the FT3. Dosing should only be done according to the FT3 AND symptoms.

I live in France. Most doctors would quite happily dose by the TSH, because that's what they've learnt in med school. However, if the patient is knowlegdable - or if the doctor is! - and asks for FT3 to be done, they usually Don't put up much of a fight. And, they will usually prescribe T3 when asked, although rarely suggest it themselves.

The whole thyroid situation is a scandal! And the patient is obliged to learn as much as s/he can, and put up a fight for correct treatment. Or, as many of us do, self-treat. If you want to get well - and lose the weight - that is often the only solution. :)


Total agreement on your comments and very informative post, I think they remain ignorant on purpose in UK more likely down to 'cost' as with everything here NHS wise it's cheap drugs and non effective ones we are ceaselessly palmed off with because the system is drained to break point !


Cost is part of it, but also Big Pharma - who control what they learn in med school - do not want them to know how to treat thyroid correctly. It's not in their interests because they are making a fortune treating our symptoms, one by one, with things like statins. Médicine is big business, there days, concern about the patient is very low on their list of priorities.


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