Changing brands of T4 - will I notice any diffe... - Thyroid UK

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Changing brands of T4 - will I notice any difference?

Belgo-Brit profile image

Hi, I believe most of you here are in the UK so you may not know this brand (I'm in Belgium and I've had to order it from France), but I am about to switch from the Belgian brand L-Thyroxine to Thyrofix and I wondered whether anyone had any experience of the latter or a brand with the same or similar ingredients? I'm switching because it contains no lactose and I'm lactose intolerant. The ingredients in Thyrofix other than levothyroxine sodium are:

- Powdered cellulose

- Croscarmellose sodium

- Colloidal anhydrous silica

- Microcristalline cellulose

- Magnesium stearate

For comparison, the extra ingredients in the Belgian brand are lactose, talc, maize starch and magnesium stearate, plus different colorants for the different dosages (I had to combine three!).

Just wondering if I'm likely to notice any effects other than the benefit of not taking in lactose every day. When the formula of the Belgian brand was changed a few years ago, I needed to decrease my daily dose.

Thanks in advance for any info you can give me.

9 Replies

I've taken many brands and never noticed a difference except for one 50 mcg tablet but found taking half a 100 mcg tablet fine (same brand). I think it is usually no problem apart from perhaps causing a small change in dosage. This isn't true for everyone, some people are quite brand sensitive. I suggest you just try it on the assumption all will be fine and investigate further if you get problems.

helvella profile image
helvellaAdministrator in reply to jimh111

When I started levothyroxine, although I was aware of claimed issues between brands, I confidently assumed I could take any of them without issue.

I thought I was doing OK until the original Teva (in 2012, I think) recall due to not delivering claimed dosage. Yes - that was what was wrong.

Since then, I have been rather more careful and aware. The differences are not always immediately obvious. I feel that Accord is OK and feels fairly even across the day, but Mercury Pharma seems to rise faster then fall off before my next tablet.

jimh111 profile image
jimh111 in reply to helvella

Yes, I've heard of problems with Teva. I avoid Teva for political reasons but it has never been dispensed for me anyway.

RedApple profile image

Belgo-Brit, When it comes to thyroid medication and doses, we are all so different. What suits one, doesn't suit another etc.As jimh111 says, just assume all will be fine, and only investigate further if it isn't :)

It might be useful, if you can, to do a basic thyroid blood test before changing brands so that you know where your levels are right now. Then you have something to compare with further down the line should you need it.

Belgo-Brit profile image
Belgo-Brit in reply to RedApple

Too late for that as I was on the verge of running out of pills, so I need to start the new ones on Sunday! But I had blood tests done about a month ago, and the new doctor checked those results before telling me to take the same dose of Thyrofix. I have to get more tests done just before I see him again in 3 months' time.

I cannot help you when it comes to Thyrofix as I don´t know anything about it...I thought there was no other T4 brand than Lévothyrox by Merck in France?!I know L-Thyroxine by Christiaens (now Takeda) was reformulated a few years ago and new version was said by manufacturer to be about 33% more effective, but I needed to stay on the same dosage. Did better on the new version, though.

The best brand in Belgium IMO was Elthyrone by Abbott. It was discontinued in 2014. I have always wondered if it was Synthroid made under another name in Europe...anyway, I did great on it, and struggled to find an alternative. I hate it when they discontinue or reformulate brands and then tell us nothing changed...when everything changed...!

I have also taken Euthyrox which was fine for a few years but stopped working after it was reformulated a couple of years ago to include mannitol. Only Euthyrox and L-Thyroxine are now available in Belgium.

It´s a shame we don´t have more brands to choose from!


I've never heard of any brand other than L-Thyroxine in Belgium, and I've been taking it for about 18 years now!! Having done a quick search, it seems Thyrofix has only been available in France since 2017. It's made in Greece.

OK! I remember the great "Lévothyrox" scandal in France a few years ago when Lévothyrox was reformulated to include mannitol instead of sucrose, and many patients went downhill on the new was said back then, especially in a French thyroid forum, that one problem was that Merck had a monopoly on levothyroxine in France...that´s all I know. I was diagnosed with hypo in Belgium in 1999 and have been on three different brands since - L-Thyroxine, Elthyrone, and Euthyrox. For some reason, many doctors prefer L-Thyroxine. One doctor tried to hide from me that there were other brands, then reluctantly admitted there were, but added: "But I prefer L-Thyroxine"...he never explained why.

Yes ,I wish we had more to choose from here in Oz. Only got 3 and all made by the same company. Aspen. Was on Eutroxsog for years, then was dizzy after I took it. Have been on Eltroxin about 6 months ,now got kidney problems. Wonder if it’s anything to do with Eltroxin or more probable my age, 85 .

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