Is is possible to be allergic to levothyroxine itself? just to the substance not to fillers?

I took 50mcg of Almus levothyroxine as I could not get anywhere with Erfa.

After taking one tablet I had chest pain, heart palpitations very strong and lasting all night and morning, tremors in my muscles- minis seizures like feeling, pressure in my head, numb tongue ( the is the least of concern), I was strongly agitated and the whole experience was unbearable. I am worried that if I do not get on well with Erfa and cannot tolerate levothyroxine then apart from T3 only there will be no medication that I cant take so ... scary to think. My last T4 was 9 ( 12-22 range) and T3 above 5 ( 3.5-6.5 range) so I am not hyper. I am in despair, truly. Especially that I do not have a GP at all now, and that is a long separate story.

IS this strong reaction a response to ingredients or levothyroxine sodium itself?

60 Replies

  • I have read:-

    Dr. Lowe: Your wife may be having an allergic reaction to some constituent of the thyroxine tablets she is taking. It is extremely unlikely that thyroxine molecules themselves are causing the reaction. Thyroxine is what we call an "orthomolecular" substance. This means that thyroxine is natural to the human body and necessary for health. Allergic reactions to orthomolecular substances are incompatible with health and extremely rare.

    I am sorry you are having such a difficult time finding meds that help. I tried Erfa too, as well as a few other NDT's but found Nature-throid suited me better (I am not saying it will suit you but it may). It is hypoallergenic and the company also make another hypoallergenic one called WP thyroid. Neither have been recalled for inconsistencies in 75 years.

  • Thank you Shaws, I am really scared now. I don't have side effects from erfa as long as i am taking 1 grain only, but 1 grain is keeping me in hypothyroid state, so I am stuck.

    Shame dr Lowe is no longer with us.

    I am waiting for refill prescription for erfa from dr S. but he was very busy recently so it takes time to process prescription. I wont be able to attend another appt. with dr S as I am not able to afford it.

    I cant still have erfa prescription repeat, without being able to see him right now, but I do not think that he would change my prescription to Nature - throid or WP thyroid without seeing me, so I am stuck unless I cant get Nature - throid or WP thyroid without prescription ? just to try;

    Is it possible to buy Nature-throid or WP thyroid without having prescription?

    I am allergic to gluten, are Nature - throid and WP thyroid gluten free? i am going to check it.

    I do think that the problem in my case might be related to the ratio of T4 to T3. NDT offers fixed amounts and I think that I need less T3 and more T4, but then again I had problem with synthetic T4 so I cannot mix and match... I do not know how to solve this problem.. sorry I am really distressed, I am stuck in a truly awful situation.

    Thank you so much for your help.


  • You can see details of Nature-Throid and Westhroid P on the main Thyroid UK website here:

    Look for Non-UK Desiccated Thyroid and click to open up the details. You can see that both are gluten-free.

    Both can be purchased without prescription but, as always, details cannot be posted on the forum. Anyone knowing of a reliable supplier should send a PM.


  • Thank you so much Rod. I have just clicked on this link. Both Nature-Throid and Westhroid P have more fillers than Erfa so I was already on best in term of minimum amount of fillers brand of NDT.

    It looks like there is no medication that could suit me. I am scared to think that this can be a case.

    I do not know if there is a point to try different brands of levothyroxine? could the bad reaction that I have experienced be only due to levothyroxine fillers?

    I wonder if anybody can be allergic to levothyroxine sodium itself just because it is synthetic hormone not produced by the human thyroid.

  • I don't think you can sensibly use a "count the fillers" approach. It is important what the fillers are rather than number. However, in numbers terms Westhroid P contains only three ingredients - Inulin, Medium Chain Triglycerides and Thyroid USP. Where Erfa has four!

    (I suspect that the desiccated thyroid powder that Erfa use also contains some form of sugar as a diluent. Otherwise not sure how they could standardise its potency.)

    If it happened to be cornstarch that is causing your problems, then Westhroid P may be very well worth trying. However it is more expensive.


  • Thank you once again Rod.

    I think I expressed myself in a wrong way, I meant probably not less fillers but less of a risk fillers, as erfa got talcum, sugar - which I thought must be least harmful and then magnesium stearate which is in most vitamins i take and I never had problem with it..

    ...but cornstarch I never thought that it could cause me problems?, I never felt sick - no GI upset from ERFA while below 1 grain but I did have GI upset after taking Armour.

    The problem is that I cannot increase erfa above 1 grain, as I experience 'side effects' - they are rather symptoms that are heart related but I must admit that I have realized some GI upset that I cannot clearly assign to increase of ERFA, but cannot exclude it either.

    Maybe my body can tolerate only the amount of cornstarch that is in 1 grain but if I supply more than 1 grain the problems begin.

    I have also speculated that it is the ratio of T4 to T3 in NDT that could be a culprit?

    I have no idea what is Thyroid USP ( part of Weststhroid P)? I never had anything with inulin or medium chain triglycerides. ?


  • You sound alot like me. I was diagnosed 4 years ago with hypothyroidism but have had a bad reaction to every brand of levothyroxine that I have tried, both tablet and solution. I have very bad side effects, extremely bad breathing difficulties and chect pain, vice like headaches, shakiness and various others, I struggle with nearly every medication on the market from basic paracetemol to anti biotics, which makes life difficult. In an effort to try and work out why I couldn't tolerate so many meds, I listed the ingredients of every tablet that I am allergic to and all the ones that I am ok with. I found that the common denominator was corn starch or derivatives of corn of which there is a very, very long list. I went to my GP and asked for a corn allergy test and it was positive. Apparently it is very rare but it is real and I definately have it, the GP has added it to my notes as it is so important. I cannot find any Levothyroxine that does not contain corn or any derivatives of corn, I contacted a large manufacturer and asked if they do a corn free Levothyroxine to which they said yes. Great I thought my search is finally over, but they were shocked when I told them that their tablets do actually contain a derivative of corn, they were only talking about the ACTIVE ingredients and I found a derivative of corn in their INACTIVE ingredients (the fillers and coatings). I am so worried about the decline in my health that have contacted my local MP about this. I don't usually get on my soap box but I feel very strongly that it is against my human rights as a British Citizen living in the UK that I am being denied access to some much meeded medication. I am supposed to be able to get free thyroid meds and yet I can't get any meds at all. Surely if consideration can be given to people with gluten, lactose, nut allergies then consideration ought to be given to people with corn allergies too, afterall if I have corn in tablets my breathing gets so bad that I feel like I'm dying. I have told you all of this just to put you in the picture and let you know that there other people out there struggling. I would suggest asking your GP to do a corn allergy test then you will know for definate, if you are tested positive, then you need to look online for a corn allergen list, you will be amazed at the amount of food, drink and medication that contains derivatives of corn - I know I was. I am going to ask my GP about trying the WP levothyroxine, it is my last hope so I pray that it works for me and other fellow sufferers. Good Luck

  • Thank you thelady2003uk. I wish you good luck with WP levothyroxine xx I would love to be able to do allergy test but at the moment I have no GP, I am undergoing complaints procedure and trying to find a new GP surgery. I didn't know that NHs can test for corn allergies. I hope to get something sorted soon, I have been fighting for so long. Love .E xx

  • Sorry forgot you haven't got a GP; You are in a difficult situation. I have just ordered some WP levothyroxine from a pharmacist that Red Apple (Administrator) on here told me about. Cost me £20 for 30 tablets, hopefully they will work. Couldn't you try ordering them and see how you get on? Whatever you decide to do good luck with everything. Take Care Sharon XX

  • Thank you Sharon. Do you mean WP thyroid ? I think that perhaps I should order some, just to give it a go. E x

  • No problem, Yes I meant WP thyroid. I ordered some at the weekend from a chemist in America, I found it recommended somewhere on Thyroid UK, I'm waiting for it to come and fingers crossed it will help, if not don't know what I'm going to do. Good Luck

  • Talc =aluminium and i suspect that is the cause of reaction with erfa

    many people are sensitive to aluminium and cannot tolerate even tiny amounts

  • The new WP Thyroid has actually less fillers than Erfa. And they are different to Erfa, so it might be worth a try.

    WP excipients are:

    Inulin, Medium Chain Triglycerides, Lactose Monohydrate

    Erfa are:

    Cornstarch, Magnesium Stearate, Sugar, Talc

  • Thank you RedApple, I do struggle with lactose :( and I am not sure how I would react to Inulin and 2 other ingredients. Ideally I would have to purchase some small amount of WP Thyroid and try it, but I am not able to do it now. E x

  • Edysia, as I understand it, the 'Lactose Monohydrate' is a naturally occurring ingredient of Thyroid USP, which is the active constituent of *all* desiccated thyroid products. Thyroid USP is the desiccated thyroid itself.

    That's why it says:

    Lactose Monohydrate*

    *Present in traceable amount as part of Thyroid USP (diluent)

    The manufacturers of Nature-Throid and WP Thyroid actually declare it's existence for the sake of absolute clarity. It is not an 'added' ingredient. It will be in the Erfa that you have been taking too.

  • Talc = Aluminium the effects of which can be horrendous as I know all too well

    my husband is chemically allergic and cannot tolerate either thyroxine or t3 but is ok on Armour

  • Hi Red Apple, Can you tell me if I can get WP Thyroid on prescription please, If not how do I go about getting it as my endo will not write private prescriptions for anything! Thanks

  • In theory, yes you could get WP Thyroid on NHS prescription on a Named Patient basis the same as for any other desiccated thyroid med. ( ).

    But if your GP / endo won't write private prescriptions, then they probably won't co-operate with the Named Patient basis either :(

  • Thank you RedApple, I do not have GP at all right now, and frankly I do lost hope in regards to when my complaint is going to be resolved and when NHS England will co-operate and help me to register with the practice outside of my catchment area. I cant count on any prescriptions at the moment. E xx

  • Thanks for this infomation and the next question: Do you know how I could go about getting some without the help of my GP/endo please. I just can't understand if a medication is available on the NHS why I can't be given it when there is no other medication available to me - I've tried all levothyroxine available in the UK to no avail. Thank you

  • thelady2003uk, Have sent you a PM :)

  • Edysia, sometimes when a body has been deprived of sufficient T4 for a long time, taking some levothyroxine can cause a sort of 'shock' state to happen. This happened to me when I was first diagnosed several years ago. I had been very ill for a long time and on the third day of taking 50mcg levothyroxine I was in A&E because my body went into shock and I lost all feeling in all my limbs, plus many other horribly scary symptoms. I did continue to take the levo and gradually things calmed down, but it took time.

    I'm not qualified to give you advice, but I think if I were in your situation I would leave it for a day and then try the levo again. I agree with your idea that the ratio of T4:T3 in desiccated thyroid may not be right for you. It may be that taking 50mcg of T4 will mean the dose of Erfa needs to be reduced a bit to ensure your T3 does not rise too high. It's a case of trial and error, perseverance and patience. Very difficult to do I know.

  • Thank you so much RedApple, that sound terrible. I am so sorry. I am so scared to try it again, especially that I have no GP right now. A&E is always an option but my hospital is not very good.

    I was thinking to stop erfa and take levothyroxine only for some time, I would be scared to mix both straight away.

    Do you still take levothyroxine? is it fillers free? - liquid/ purified?

    I am sorry for asking so many questions but I have no other ways of finding things out.


  • Hi

    I asked a similar question I took armour then switched to erfa but still have palpitatations. Someone gave me a link to stop the thyroid madness page on why NDT does not work. On the page it states a reason for palpitations as low iron. I do have low iron so that might be something to think about. I am going back to doctor soon so will let you know what he says also.


  • Hi Piplysmelie. Thank you for your reply. I do have low iron but I am taking supplements to correct it, heart palpitations are not the only problem, when I try to increase the dose to over 1 grain I do get stomach upset :( but on lower dose my stomach is fine, but I am still hypothyroid and my t4 is very low - only 9 ( 12-22 is the range).

    It is all such a puzzle. I am getting really ill, I am not sleeping at all.

    I wish you good luck with your doctor. Edysia xx

  • Far too many doctors and endos are ignorant of the fact that your ferritin mudt be at least 70 in order to utilise levthyroxine or any form of t4

    hence its vital to correct the aneamia with iron plus 500mg tablet of vit c at least once or twice a day

    also other vitamins and minerals become severely depleted in hypothyroid so taaking a good multivitamin is recomended

  • Just in case you didn't see this extract from Dr Lowe's website above dated September 6, 2001:-

    Your wife can test whether she's having an allergic reaction by taking an antihistamine, such as 50 mg of diphenhydramine HCL. She should take the antihistamine an hour or so before taking her next dose of thyroxine. If after taking the antihistamine, the thyroxine preparation doesn't cause the reaction, it’s safe to conclude that she’s having an allergic reaction to some constituent other than thyroxine in the tablets. In this case, her doctor should switch her to another brand of thyroid hormone.

  • That is a great idea Shaws ! Thank you so much. I don't think that I can get dipenhydramine HCL here. I am wondering if ordinary OTC piriteze would help or any other over the counter antihistamine ? Thank you once again. I am truly grateful for your advice. E xx

  • There are quite a number of products that contain diphenhydramine - the following contain ONLY that as an active ingredient:

    Nytol Original 25mg Tablets

    Nytol One-A-Night

    Boots Sleepeaze 50 mg Tablets

    Boots Sleepeaze 25 mg Tablets

    Note that in the UK it tends to be regarded as medicine to help with sleeping whereas in some other countries they regard it as an antihistamine.

    Don't think it matters very much which antihistamine you use - they all tend to be moderately effective. Some last longer than others. Some are less likely to cause drowsiness. Some people don't like the effects of some of them. So loratadine, or cetirizine should be fine.

    Of course, you might need to be looking out for the excipients (ingredients other than the active ingredient)!


  • Thank you Rod, you are a mine of information and a thyroid guru :) I will check out Nytol. I used to take it ages ago for my insomnia, that was at times when antihistamines were able to make me sleepy, which is no longer a case. Edyta

  • Just quite good at finding things! :-)

  • Very good :)!!

  • I'm going to jump in here with my personal experience of diphenhydramine (the Nytol brand). I took one at bedtime hoping it would help me to sleep, but I did not sleep well and actually became severely depressed by the third day. Many people seem to tolerate this 'old style anti-histamine' and get good results with it, but I would never touch it again.

    If you want to try anti-histamines to see if they help, then I would try the generic ones that are sold OTC for hayfever etc. The branded versions are more expensive and are no different, so don't buy them!

    I use all of the following with no negative effects (not for hayfever but for allergic reactions especially to foods)

    Cetirizine (branded versions include Piriteze, Zirtek)

    Loratidine (branded versions include Claritin)

    Chlorphenamine (branded version Piriton)

    Chlorphenamine is short acting and can cause drowsiness, so might be helpful to take before bed. The other two are less likely to cause drowsiness (although some people do get drowsy with them).

  • Antihistamines do tend to make me depressed they are CNS depressants and paired with my tranquilliser, mianserin ( tetracyclic antidepressant ) and codeine based painkillers I do not feel great after taking them, however the idea was to take antihistamine before taking levothyroxine just to see if it would alleviate side effects of levothyroxine and if it did it could indicate that excipients in levothyroxine not levothyroxine itself cause this horrible heart palpitation, shortness of breath and tremor, which I have expierienced.

  • Ps. RedApple : for food allergies do you take antihistamine before -to prevent or after allergy symptoms occur? Ex

  • Both! If I know I am going to eat something that will cause a problem (e.g. smoked fish or shellfish, bacon, aged cheese etc), then I try to remember to take it before I eat. But sometimes I forget and only realise when symptoms kick in. Other times, I get an unexpected reaction to something and have to take antihistamine quickly!

  • Thank you. E xx

  • If you haven't done so, try different ones. You may find one that helps without the depressing effect.

  • I have just experienced the worst case of reaction to a generic brand Eustroxsig which has dyes & fillers in it.I had been taking thyroxine for 13yrs.Trying to convince Drs it was thyroxine it was the pharmacist who said cease it.My Tsh has really never changed even though its now 5mths.I would be very cautious as it takes months to get out of your system.

  • Thank you so much Marylyn. It is so awful. I know the pain. What are you taking now? Exx

  • At the moment only magnesium,Vit d,B12,salmon oil,coQ10 .I have also mod -severe sleep apnoea.Have thyroiditis according to U/s.

  • Ok. Thank you. So you don't take any thyroid meds at the moment? What's your t4 and t3 levels?

  • Sept.TSH1.0 ,T3 4.9 T4 15 since then I have low cortisol & B12.also inflammed liver.Thank God for holistic Drs who care & who dont tell you it is stress.

  • I edysia2,

    I can sympathize very strongly with your feeling of vulnerability.

    I had a really bad experience with the Almus make of levothyroxine last year. I had taken one pack with no problems, then the next was seriously bad to the point of being potentially lethal. I think there was very little 'goodness' in it. An excellent adviser with the British Thyroid Foundation told me that it is the worst make. I have written down the make she takes which she believes in the best: Upharma which is made in Barnstable, and comes in all 3 of the British sizes. -- I haven't checked that spelling out mind!

    Personally, I am now on liquid thyroxine which is very accurate, and allows the dose to be changed by one or two micrograms at a time, avoiding shocking the system. And I have split my dose into twice per day, which avoids a flood of the hormone into the blood. Twice per day feels more natural and I was immediately more at ease when I changed -- much better.

  • Thank you so much Helena! Your advice is great! I will write down the name of this brand and if I ever get to see any doctor then I will ask for Upharma, Barnstable. Splitting the dose into 2 seems to be a great idea too. I never thought that you can dose levothyroxine twice a day.

    May I ask which brand of liquid levothyroxine do you take? E xx

  • Helenabc,

    Upharma which is made in Barnstable, and comes in all 3 of the British sizes

    Can you please find out more about this thyroid medication and get back to us. I have never heard of it!

    That said, I wonder if there is some confusion going on here. Almus is NOT a make of levothyroxine. Almus is only the name used on the boxes of generic medications supplied through Boots pharmacy. Boots do not make their own levothyroxine. They simply supply other manufacturers levi inside their own Almus packaging.

    Most often, when you look inside the Almus levo box, you will find that the name on the foil backing of the blister pack, and on the PIL (patient info leaflet) is Actavis. And Actavis is in Barnstaple.

    So, I am wondering whether 'Upharma' is yet another generic pharmacy packaging name, and the tablets inside this packaging are actually Actavis? Having said this, Actavis have not (until now anyway) made 25mcg tablets. So any 25mcg tablets in this 'Upharma' box will most likely be from another manufacturer. Currently, the only 25mcg levo tablets are supplied by Wockhardt and MercuryPharma.

  • sorry for jumping in here. I am wondering which form of levothyroxine has the least amount of fillers, would that be Eltroxin ? I know of liquid form of levothyroxine- Tirosint but that is in America.... my head is not in a best shape today as I did not sleep for the last 24 hours:( and I am all consumed by chasing my complaints and finding GP practice.

  • It is a pity that someone representing the BTF is so woefully out of date or wrong.

    Disentangling this information I think the story is something like this:

    There used to be a levothyroxine product made by Alpharma.

    At some point this became the product we now know as Actavis. I think this would have been in 2005 when Actavis acquired the human generics business from Alpharma.

    Actavis is ONLY made in 50 and 100 microgram dosages.

    Almus is a brand owned by Alliance Boots. Their levothyroxine product is actually simply Actavis packaged in Almus wrapping. [Note: There is no guarantee this will always be the case, the contract could change at any time. Always check on the patient Information Leaflet.]

    So, if by some miracle I have understood things correctly, the BTF adviser is saying, at one and the same time, that the Actavis product is both the best and the worst?

    As I have said many times, there are currently only three companies that hold product licences for levothyroxine tablet products on the UK human medicines market and actually supply product: Wockhardt, Amdipharm Mercury and Actavis.

    The report on levothyroxine from the MHRA has some information:


  • Hi Rod. I am wondering which of these : Wockhardt, Amdipharm Mercury and Actavis have the least amount of reported side effects? Are there any stats out there?

    And what is the score with Teva, Eltroxin liquid levothyroxine? in a liquid form wouldn't they be hypoallergenic?


  • Hi Rod, I noted in the MHRA report they mention Recipharm, which I think is Swedish. Do they actually distribute to the UK market? I am only aware of Actavis and MercuryPharma (is that the same as Amdipharm Mercury?). Thanks. Liz

  • I am very glad you posted that. Absolutely - Recipharm do not market any human levothyroxine product in the UK. And yes, I think they are Swedish.

    Amdipharm Mercury Company Limited markets some products as Mercury Pharma, others as Amdipharm.

    In addition to Actavis and Mercury Pharma we have Wockhardt (25 mcg only). We also see Alliance Boots who market under their Almus label, and Lloyds who market under their own name. Both are, I believe, actually Actavis but do check the PILs.


  • Thanks Rod. I get 100mcg and 50mcg from Boots and it has Almus on the packet but the PIL does say manufactured by Actavis. My 25mcg tablets are Mercury Pharma. I don't think I have ever had Wockhardt - I seem to remember seeing some problems with some of their drugs, but maybe not thyroxine. It is interesting to note that from January 2014 they are all going to have to comply with new dissolution testing. Will it make any difference to stability of the products? Who knows. Liz

  • I took Wockhardt Levo for 10 weeks and didn't get on with it at all. Stopped thyroid meds for now. I don't believe all the reassurance about orthomolecular status of it ie: that it's indistiguishable from human hormone.

    I am sensitive to many meds, though.

    On the drug safety front another report came out on a second plant of theirs[Wockhardts] in India, this month. reading between the lines some meds were not pulled like others listed] due to the disruption it would cause and also the fact that a lot of the issues were technical cross transference lapses - but tbh, the production ethic didn't sound exactly top class.

  • The liquid thyroxine all seems to come from the same factory in Holland at present. Some is labelled /sold by TEVA and some labelled/sold by Eltroxin, and they appear to be identical. The only disadvantage is that it is very expensive (for the NHS to pay for) so I only get one bottle at a time, lasting some 3 weeks!

    I didn't think of trying twice per day until I read of other patients doing this. The main reason that once per day is recommended is to maximize what doctors call "compliance" -- the less often people have to take something, the more reliably they take it.

    The tablets from Barnstable are not a "brand" but just a generic make.

  • Thank you for clarifying this, I really appreciate your help. Best wishes. E xx

  • On the subject of tablet makers, I think I had best 'phone the adviser again and ask her what it is she takes. I know for sure she said, though the company owning the production had been taken over, she had been assured that they were still made on the same production line at Barnstable to the same formula as before the take-over/combination/whatever went on on the business side. Also, she said that the BTF had persuaded this company to also make the 25mcg size.

    The ones that had a bad effect on me were labelled Almus Actavis, but they may simply have 'gone off'.

  • To my understanding, the manufacturing facility in Barnstaple is the old Alpharma location taken over (in whatever way) by Actavis. I am ready to believe that the product is unchanged.

    But, again to the best of my knowledge, they do not currently produce a 25 microgram tablet.

    It is, obviously, possible that such a product is in development or even has been submitted for approval. I wouldn't know anything of that.

    Interestingly, the 25 microgram tablets have been oddities in lots of ways. When Teva had a levothyroxine product, they produced their own 50 and 100 mcg tablets, but the 25 mcg dosage was actually the Eltroxin product. It is also odd that Wockhardt make 25 mcg but no other dosage for the UK market.


  • Thank you, helvella, for making everything straightforward!

    I now understand that "reply to this" is different from the "reply" at the bottom.

    And the adviser lady did say "Alpharma": I failed in reading my own bad handwriting! I had written things down during an hour's lively and interesting telephone conversation in which I didn't have a free hand to steady the page. I am sorry for the confusion I caused yesterday.

    So, is it known whether Actavis make all their thyroxine tablets at the Barnstaple factory, or whether they also use other factories?

    I believe that patients need all three sizes of tablets to be manufactured by the one company, to the one formulation. The lack of matching 25mcg options has been deplorable.

  • In case you did not know, if you click on Reply to this your reply will be indented under the post you reply to. And the person you re responding to will get an alert. Helps to keep the conversation flowing.

  • I take 25mcg levothyroxine and I've been having chest pain and heart palpations. My doctor said to stop taking my meds for a couple says then start taking half of it. I'm new to being hypo.

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