The current Teva levothyroxine in the UK was introduced as a brand new formulation around 2016. (There was no Teva levothyroxine product for a few years - approximately 2012 to 2016.)
Teva introduced 12.5, 25, 50, 75 and 100 microgram dosages. These were the first 12.5 and 75 levothyroxine dosages ever in the UK. Potentially very convenient.
Reports
As the number of people getting Teva levothyroxine increased, we saw a number of reports from individuals which identified they felt unwell when they took Teva levothyroxine - issues which did not occur with other makes.
Slowly, after people had swapped makes, and maybe tried Teva more than once, it started to look like there was a problem for some people with Teva levothyroxine.
However, alongside these reports, others were saying how Teva was the best levothyroxine they had ever taken.
Explanations
1️⃣ First, Teva was the only lactose-free levothyroxine tablets in the UK. Therefore, anyone with problems tolerating lactose might well find it better for this reason. (Since then Aristo Vencamil and - though availability is an issue - Glenmark have been released. Both of which are lactose-free.)
2️⃣ Second, Teva’s only unique excipient is mannitol (E421) so it is natural to suspect that could be a cause.
This suspicion had some backing from issues which occurred with Merck’s levothyroxine when the formulation of that changed - first in France, then around the world. The new formulation more or less swapped the lactose out and replaced it by mannitol. And there were reports from several countries of issues some of which were similar to the UK Teva issues.
3️⃣ Third, Teva levothyroxine, along with Advanz/Mercury Pharma levothyroxine (including UK Eltroxin) contains acacia. Despite research into acacia finding few issues, this has long been suspected to be a problem excipient for some people.
4️⃣ Fourth is “anything else”. There might be factors including some which we would never suspect.
What do do?
▶️ Always check the product you have been dispensed - while still at the counter in the pharmacy. This is plain sensible advice for all medicines.
▶️ If you find Teva levothyroxine and have found it fine in the past, then you should still be fine. Indeed, you might find it the best formulation available for you.
▶️ If you find Teva and have never before tried it, accept it. When you get home, swap to Teva as soon as possible. That way, if you have a problem, you probably have some of your previous prescription to tide you over while you sort the issue out. And make a Yellow Card report.
▶️ If you find Teva and have previously had issues with it, ask the pharmacy to exchange it.
▶️ Be aware that AAH Hillcross levothyroxine - in the 25 microgram dosage ONLY - is actually Teva product.
▶️ Also make notes of all levothyroxine products you receive, any changes (good or bad) you associate with taking them. We all tend to think we will remember everything but, very often, we don’t.
These are all simple enough in themselves. But they can be complicated by unhelpful attitudes of prescribers and pharmacists; if you are on multiple dosages; if you are taking other medicines.
You can take other steps to ensure you do, or do not, get Teva in future. But I’m trying to limit the size of this post!
Yellow Cards
Many of us on the Thyroid UK forum repeatedly advise that anyone who has issues with any medicine to make a Yellow Card report.
We do not know any way of identifying in advance who will, or will not, tolerate Teva levothyroxine. Only if you categorically know you have an issue with one of its excipients.
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If you do not try it when you have the opportunity, you could avoid having an issue, or you could miss out on what might be the most available levothyroxine and what might possibly be the best levothyroxine for you.
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Written by
helvella
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Thank you. I experienced problems with Teva brand Levo, when it was issued as an alternative on two separate occasions.. Both times , I had headaches, and just felt below par. The pharmacist checked the contents label, and pointed out the mannitol- in his experience, mannitol causes problems , eg headaches, for quite a few people,whatever it is in, so one to watch out for.
I didn't want to ignore that it could be something else - for some people.
And, while I did not get on with Teva levothyroxine, I can tolerate similar amounts of mannitol in other products - including mints! But I only have the odd one or two. Maybe - for some of us - it is a specific issue of mannitol in a levothyroxine tablet - the combination being part of the problem?
I think part of the issue will be that simply changing to any different brand can make some people feel off, even quite ill. Something I have learned over time. Happens even with NDT.
In that case can a person who makes a sudden switch where they may still have the old Levothyroxine in their system, or their body has adapted to the previous brand, really be sure the symptoms are purely down to the TEVA itself?
I remember feeling really sick, to the point I was trembling and couldn't walk after a sudden switch from TEVA to Mercury Pharma during Covid lockdown. I blamed the Mercury Pharma. But it occurred to me over time that my reaction may have been due to being forced into switching suddenly and had I had several weeks of no levothyroxine at all, then started on the MP, I might have adjusted better.
Of course many do have issues with the Mannitol, no question, and Teva is noticeably different, I find, from some other brands, but over time I have come to appreciate that there's a feedback mechanism in tolerating medication that can't just be overridden without consequences sometimes. Switching suddenly between any brand, I doubt is going to go down well with some people, even if it's ostensibly fine for others.
A similar phenomenon can happen when stopping your meds entirely during a period of madness, or unwelcome necessity and then restarting with the same brand at the same dose and...nothing happening...remaining hypothyroid despite that dosage having been fine before. Even finding you can't tolerate that brand as well as you used to. This thyroid replacement thing can be a delicate, unpredictable dance.
The issue I was trying to address was primarily that many members appear to think they MUST avoid Teva. That Teva is in some way a POOR quality product. That if they take Teva they WILL feel terrible.
I can understand that repeated comments and warnings about Teva do tend to give that impression. And I wanted to clarify the situation - at least, as far as I understand it.
There are, currently, seven formulations of levothyroxine licensed in the UK. I can imagine anything from people who can take any of the seven, through to others who find they can only tolerate one, and every possibility in-between! And the differences being anything from "is it a different tablet?" to "never again!".
Be aware that AAH Hillcross levothyroxine - in the 25 microgram dosage ONLY - is actually Teva product.
oopsy, I was given a packet of Hillcross 100mcg Levo and refused it because I assumed all Hillcross was Teva. So if offered again (as I usually have Accord), should be ok?
You can always look at the actual card outer - it will say the PL holder. Or ask them to look!
It isn't always as easy to make it clear, but I do try in my UK medicines document:
helvella's medicines documents (UK) can be found here:
helvella - Thyroid Hormone Medicines
helvella has created, and tries to maintain, documents containing details of all thyroid hormone medicines licensed in the UK and, in less detail, many others around the world. There is now a specific world desiccated thyroid document.
I highly recommend viewing on a computer screen, or a decent sized tablet, rather than a phone. Even I find it less than satisfactory trying to view them on my phone.
helvella - Thyroid Hormone Medicines - UK
The UK document contains up-to-date versions of the Summary Matrixes for levothyroxine tablets, oral solutions and liothyronine available in the UK. Includes injectables and descriptions of tablet markings which allow identification. Latest updates include all declared ingredients for all UK-licensed products and links to Patient Information Leaflets, Dictionary of Medicines and Devices (dm+d), British National Formulary, NHS Drug Tariff, etc. PLUS how to write prescriptions in Appendix F.
Also includes links for anti-thyroid medicines (but not product details).
May I add this too? If you know you are better or worse on a specific brand of thyroxine, you can give your surgery and pharmacy the government advice on this, and have that brand detailed on your record.
Content on HealthUnlocked does not replace the relationship between you and doctors or other healthcare professionals nor the advice you receive from them.
Never delay seeking advice or dialling emergency services because of something that you have read on HealthUnlocked.
