Thyroid UK

Are all UK brands of Thyroxine created equal?

Hi there,

I see from the list on here: that there are quite a few different brand names that manufacture Thyroxine /T4 tablets.

My question is - are they all pretty much the same?

Are they interchangeable?

Is there any one brand that has a bad or conversely a very good reputation?



2 Replies

There are actually only three formulations in the UK. (Well, for a while yet, there is the ever-so-slightly different formulation of 50mcg Mercury Pharma levothyroxine - see link below.)

The establishment often appears to assume that they are interchangeable. Some people seem to manage to switch with little bad effect. Overall, though, we see a lot of people finding one much better (or much worse) than the other two.

I don't hold with reputation - it is what works for you that matters, not what others might have thought.

There have been quite a few papers that have shown switching can be a problem. Much of that research was done in the USA where there are considerably more formulations available (though fewer than even a small number of years ago).

Although I have tried to pretend that they are all the same to me, I have reluctantly come to believe that they are not. On Actavis I feel overall under-dosed. On Mercury Pharma I feel over-dosed shortly after taking them. I have not had a prescription of Wockhardt-only since I was starting.

A classic example of them not being the same was the Teva formulation which had its product license withdrawn (for the 100mcg dosage). See the report linked here:



Thanks Rod for your insight. It's interesting to hear about your experiences on the different ones.

Thanks also for the links. :)


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