I have both brands which I believe are both Merck. From different parts of the globe.
Recently I ran out of 100’s from one continent which I had been on for maybe a year and so started to use Euthyrox 50’s instead. I’ve been on them approaching 3 weeks now.
I have started to wonder if they are actually levo at all. Feel crap. Looked at the excipients, one of which is mannitol. I think this is in Teva.
Obviously I thought these both made by Merck and upon looking both seem to contain Mannitol and yet all the doses I had in Eutirox worked well for me and bought from an online chemist. Whereas the other were bought by a relative from a bonafide chemist abroad.
I know it’s a long shot but has anyone else had an issue between these two brands?
Any info appreciated. I hate chopping and changing brands but am going to start on some accord now as luckily I have some although not much.
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Yeswithasmile
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A few years ago, Merck started to changeover from lactose to mannitol. They rolled the new formulation out across Europe and appear either to have completed, or are getting near completion, across the world. (It's possible the old lactose version could remain available for a while - difficult for us to be sure.)
Yes - Teva levothyroxine (at least in Europe and the UK) contains mannitol.
I don't know why they are affecting you differently and have no good ideas, I'm sorry to say.
It was only last night, because I although I have noticed changes in brands before, combined with thinking I had given it long enough to settle a bit and I still felt rubbish that I decided to look. I noticed on the Euthyrox it said ‘modified excipients’ followed by the mannitol. I recalled feeling like this on Teva and the only thing I came up with was the mannitol then
It’s a real shame as I can get Euthyrox easily and it’s literally £4 a pack. So cheap. But now I’m back to rethinking it although the Eutirox will do same if you’re correct in saying it’s a worldwide roll out.
Whilst I consider it too small and limited a trial to justify such a large change, worldwide, they did look before launching. As in so many trials, they used healthy volunteers. And found very little difference in blood levels from the change to mannitol.
Perhaps we'd see differences in people who are hypothyroid? Or, simply, from a larger scale trial? Or based on individuals rather than populations?
Merck now publish documentation in markets when they change which says that dose adjustments might be needed.
This paper says the trial process was misconceived:
Levothyrox® New and Old Formulations: Are they Switchable for Millions of Patients?
And I'm not convinced that this is the result of better stability of the product and improved absorption - which have appeared the main suggested mechanisms.
you’re right of course. We do need to know what is going on and obviously I feel very frustrated.
It is impossible for me to tell if the difference equates to a drop in levels for me unless I test. I’m not going to do that as now I’m going with my instincts in that I’m not coming down with flu and that it is the medication, I’ve already switched over to accord. In an ideal world I would test this week but I want to try and feel better 🤷♀️ Therefore delaying the switch is not something I want to do.
I’ll be interested to read the link and the comments on it too. It’s disappointing to think that it’s possible for manufacturers to change their formulation without comprehensive investigation and wonder if the reason is simply cost?
Personally I just think mannitol may alter cell function rather than absorption. I need more research but suspect this is why some people with neuro diseases take large amounts of it. For me that would be similar to how adding oestrogen feels. No difference in levels but a world of difference in how bad the body feels.
Merck had been asked by the French government to look at making this change. The aim seemed mainly to improve shelf-life - and more to avoid deterioration during that life than extend it.
The trial process was based on existing standard protocols. And no-one in this paper is alleging anything was wrong with it except in one regard - numbers of subjects.
Yes. I see that now I’ve taken a look. Whilst the letters seem to be behind a paywall, the replies are not.
It appears that interpretation of the data is subjective. The problem being all the differing opinions just makes it really mean nothing as far as I’m concerned. Yet again.
Curious. I was on Erfa, but as I am in France post Brexit I needed to change to a local brand and was prescribed the equivalent by Merck, this time called Euthyral. I felt awful and managed to get some more Erfa sent across. But when these were running out again, I decided to make the changeover really slowly, by cutting both brands into fragments and gradually increasing the proportion of Euthyral over the course of 2 weeks.
This seems to have worked better.The Euthyral is 100mcg levo and 20mcg Liothyronine (T3) and the excipient is lactose here - I am taking 3/4 tab. I have an extremely unhelpful new GP who will only test for TSH so have only subjective impressions - I have ME/CFS and don’t think my extreme fatigue is necessarily due to thyroid right now, but I might consider pushing up my dose a bit to see if it helps, once I get my THS reading . Your post made me think about this, thank you.
I don’t know if it’s all about dose here but you can only try.
The ones contains lactose aren’t a problem for me. I don’t know if it’s mannitol to be honest but it’s the only link between the two.
I would say that once I started dealing with my thyroid my self I pushed my dose up further than the doctors ever have. I feel much improved with t4 60% of the range. Doctors treat using tsh which is inadequate for me.
Lastly I have diagnosis of me, fibro and hypermobility all much improved on a higher levels 😊
I appreciate your reply, all that resonates with me incl. needing increasing doses of some supplements with this kind of diagnosis. Wishing you all the best with these difficult health issues. Thyroid is basic and should be the easiest to stabilize. I hope!
Does the Eutirox you are taking contain lactose or mannitol?
Merck have made an effort to change the packaging everywhere, as their mannitol version replaced their lactose version, so that patients would (hopefully) notice and check further. Has yours changed packaging? And which country was it intended for?
I have Eutirox 150mcg. I have been using this for ages 3 x a week. Along with 100’s and 25’s too. These didn’t cause the issue. I, wrongly, assumed that Euthyrox would be same.
The problem now is that if I go back to Eutirox will it now contain mannitol which seems to be my problem.
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