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HYPER Carbimazole Dosage

Just wondering... What is a usual dose of Carbi?

I know that it all depends on levels...

I was diagnosed HYPER 3 weeks ago, TSH <0.01 T4 51.1

I have been on 40mg every morning of Carbimazole. 3 weeks on I have just had a trip to A&E with widespread fiery welts/hives on me, head to foot, it was awful... They did bloods... TSH still <0.01 but T4 down to 42. Hospital told me to continue on same dosage until I see Endo in 7 weeks....

Is 40mg Carbi a standard dose for my T4 level 51.1?

Theoritically could this dose be reduced yet?? As I have dropped to 42 (I know this is still high!)

I took only half dose today 20mg, hives were very much less and more bearable.

Appreciate any insights, docs at hospital seemed to think 40mg was quite a high dose, and I would love to be able to get it down a bit....

TIA :-)

38 Replies

Hi wildpoppy, I had a similar reaction on the same timescale as you, I.e. after 3 or 4 weeks on Carbi. Prior to that I was suffering from sore throat which I saw gp for. He dismissed the idea that it was a side effect. I woke up one morning covered in Hives and went straight back to see him. His comment was 'You've got a real thing about this drug - it must be something you've eaten'! He gave me a script for Piriton. I told the Chemist, he checked and confirmed that they were definite side effects of the Carb. Fortunately I had an apptmt with endo a week or two later and he said to continue on same dose, but ordered blood tests to check liver and kidney functions etc. By this time the hives had all calmed down but I think I was on a bit lower dose than you - it was a long time ago! However the antihistamines did help when the hives were at their worst. Good luck, Val


Thank you Val, flipping GP's!! They are a menace!

It seems that some people are experiencing hives on this drug... I must admit the hives I had were pretty scary, they were so big they joined u to form huge patches of swelling and redness all over me...

Yes, the anti histamines help... Although I admit they didn't stop them completely. Which is why I lowered my dose... But I don't think 20mg is probably enough at my level :-(

Thank you for your help, as much as I wouldn't wish it on anyone, it is nice to know that someone else has experienced something similar :-)

How are you now Val?


I'm ok (ish) now, thank you for asking. After several bouts of hyper stretching over many years I had RAI and wish to goodness I hadn't bothered. Now hypo with all the complications that go with that one! Did the endo not prescribe meds to slow your heart rate? I was given Diazepam. They usually prescribe beta blockers but they trigger Asthma for me. Hope you feel better soon and get everything back on an even keel.


GP's?Endos like to get your levels down quickly because of risks to the heart. Why dont you just ask to change to PTU?


Yes I will, as soon as I get to see an Endo...

(The last time I went to see my GP because of medication, she sent me to A&E to do it? My GP is so great that he argued with me that my Coeliac Disease isn't autoimmune... OMG! At this point I gave up!!)

My Endo appt isn't for another 7-8 weeks, which will make it nearly 11 weeks from when I started Carbimazole....I rang the Endo's secretary, and spoke to an Endo who said that was a normal time sale, not to worry and to watch out for a sore throat?!

I think I will ring again today, but they do make you feel like you are being a nuisance :-(

My resting rate has come down from 120 to 90 in 3 weeks... Not down completely but better than before... I just hope taking Carbi at half dose for a few days until sorted doesn't shoot me back up again.... Thanks Silver Fairy


I don't have an answer regarding the medication but it is clear you need to find another GP. Is there another practice near you which is accepting new patients? Do they have good reviews from patients (I think some GP practices game this but it is something to look at)?


Thanks Knotty I will check, unfortunately, all of my GP's have been useless except from one that was awesome... But I have moved far away from him now :-(


That's the right dose until you get your t4 down to about 21 and your tsh starts to rise. Then you can drop down a bit to 20 mg. it's taken me 4 months since April to titrate down from 20 mg a day when my tsh was 0.02 /t4 24 to 5 mg a day tsh now 1.8 and t4 at 13.8. Alex. I have hyper due to graves.


Ps. I have never had hives with the carbo. I was on 40mg of carbo a day for a year previously as part of my block and replace regime. Alex


Thanks Alex

I have just spoken to an Endo, she said she is happy for to stay on 20mg for a month, then check my levels again... In the meantime I have to take AntiHistamine for the hives... She said that it would just take longer to get my levels down at that dose, but she would prefer me to stay on Carbi if possible, and reluctant to give me PTU at this stage... Though she won't clear why?! Many thanks Alex


Hi Wildpoppy

I was pretty ill one year ago ... and to save a very long story I had just about every symptom of Hyperthyroid, actually, I Graves' disease, as I have antibodies..

I was put on 20mg per day of Carbimazole for around three months then down to 10 mg ... then again down to 5mg

at the doses I took... I never had hives , thank heavens.. and I felt myself become well again. After around 10 months after starting in Carbimazole I felt much better .

I supplemented all the way through my Carb treatment

with many vitamins and minerals to boost my immune system , as I felt very strongly that it was my immune system that was haywire .... not my thyroid !

after 1 year......I am Euthroid I.e.... normal .

and I continue to treat my immune system with my supplements in an attempt to stay that way.

I don't really think I could have done it so successfully without the Carbimazole ... to begin with but couldn't wait to get it out of my system all the same . It served its purpose well for me.

I'd much rather take natural supplements ... which I now

take daily , as I know they improve my energy , sleep pattern, hair, nails , skin , bones , brain fog, itching, sweating , joint pain....and dreadful anxiety

so good luck with your Carb... I think 20mg of it is a good

dose to start with and worked very well indeed for me .



So what supplements do you take ? I don't take any. I assume you don't take carbo anymore right? How long where you on 5mg a day before stopping? Thanks Alex


Hi Madge

Thank you so much for that email, its very reassuring :-)

The Endo said today that she was happy for me to stay on 20mg, assuming I could tolerate the hives ( I am on antihistamine for it now, so more rubbish in my system:-(....)...

I also am supplementing, and as I am coeliac I don't eat gluten... Also, i have cut dairy as I believe it could be helpful. I muss my glass of red wine every now and then, but as my heart rate hasn't dropped down yet, I dare not have any!!

May I ask what your symptoms were? Did you have a high heart rate? Do you remember your T4 level... I am told mine at 51 was substantial, butI don't really have anything to compare to...

So if you are now euthroid, do you still experience symptoms?

Thanks so much for answering <3



PTU is not a nice table , it can cause bad reactions too. Maybe she should have told you this . If you can cope on carb i wouls stick with it , unless you have reason not to. Your levels will go down and your TSH will raise a little , this is when you will feel better.As for your doctor let me tell you' dont expect alot if anything , be ready for your symptoms to be blamed on anything but your thyroid .I hope you get a good endo but again do not expect to much from these people once your levels start to come down they will loose intresrt in you . When I was first diegnosed with GD 20mg did nothing it took 30mg to hammer it down . I hope you feel better soon your best action for yourself is to educate your self , for your GP will no less than you . I wish you all the best and hope you feel better soon


Hi Wendy

I will try to stick to Carbi, thank you, yes... I guess it depends if I can control the hives... I am hoping they disappear like for some persons on here? Fingers crossed! I am on 20mg for a month, though I have been on 40mg for 3 weeks... the 40 mg brought my T4 from 51 down to 42 in three weeks... The endo said this was good going, but again, I have no idea?!! So I am hoping 20 will do it, and the hives bugger off!

I completely agree about not expecting a lot from the doctors... I have experienced this when diagnosed with Coeliac Disease 4 years ago... I tend to rely on my own info (which is why I am here :-) )....

Thanks for all the help



I started on 40mg for a month and then dropped down to 20mg with an inital T4 reading of 59. As a result my T4 reading came down nicely within range. Rather than the dosage I would be concerned you are not tolerating the drug. Contact your endo or failing that your gp.


Do you think that the hives means I shouldn't take the drug? This is what worries me... The Endo said to me TODAY to take antihistamines with lower dose of 20mg... She said to try and stick with it... I know some on here that seemed to have a similar reaction also, and they took antihistamines...

I continued today with 20mg... I did still get hives, and rashes, but not as bad as Sunday (which was scary and unbearable head to foot)... Today has just been random bits and bobs, a little patch here and there etc... I have taken some piriton...

Thanks for your help :-)


some patients take more than 40mg. it depends on your level of the hormone and your symptoms. do not be in a rush . in this disease you must be patient as possible as you can to lower any other complications. i am taking carbimazole for two years and a half now with a dose of 20mg and it is ok for me . my all tests is normal but i am taking it because of the symptoms associated with reducing the dose. you have to be the doctor of your self and decide what to take


Thank you elsaba

Do you mean you have taken 20mg for 2.5 years? And you do not lower it because of symptoms of reducing the drug? May I ask what symptoms you have when you take the drug? Do the doctors not tell you to come off Carbimazole if your tests are normal?? Sorry, so many questions!! I thought when you are Euthryoid, that you no longer had to take drugs?

Thank you


i became Euthryoid but when i reduced the dose t3 started to raise.the symptoms was palpitation,severe anxiety,fast heart beats and difficulty sleeping. the problem is it takes several weeks to lower t3 again by increasing the dose of carbimazole. the doctor asked me to reduce the dose but i can not because of the symptoms i mentioned that is why i am telling you to listen to your body because the normal range of any test vary from person to person but most doctors do not care about this .they just look for a normal range

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I see, I understand what you mean now, thank you. Oh thats awful for you... Wow. I hope that with time your body starts to be able to wean off the drug... Hugs to you

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So as an update tonight, I spoke to Endo today... She encouraged me to stay on Carbi, at 20mg...and take Antihistamines... Apparently many are able to manage like this.

I have done this today, I came out in some random rashes and hives... Not too bothersome, except tonight, I took some Piriton as I seemed to be getting more pop up. I have to retest bloods in a month to make sure its working, or call them if HYPER symptoms get worse again, or reaction gets worse. Ho hum.

She told me I tested positive for Graves :-( So there we are... Its a waiting game!

I am supplementing, and cutting stuff out of the diet... Hoping to beat the beast!

Thank you so much for everyones responses... Truly appreciated from the bottom of my heart, Its been a tough few weeks, as I am sure you all already know!! <3

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You might find that your choice of antihistamine is also of some significance. Some last longer than others, some make you drowsy, etc. It could be worth having several and changing regularly.

For example:






Thank you Helvella

Thats a good idea, I'm on Piriton (cetirizine)... its euphoric, and everyone has a glow! Not good for driving though! I will check them out... Cheers

May I ask...( I know that it is t4 level & Carbi dose dependant)... But as guesstimate... with a T4 42, dose of 20mg how long until levels drop a good chunk?

Obviously I know the variables, I guess I am asking the impossible!! But do you think it is unreasonable to expect them in the early 30's in a month or two?

I ask as I have a holiday end of Oct... I had to cancel this summer one, I'm loath to cancel another :-( I really need it! But obviously don't want to go if I still have symptoms etc

Many thanks


Piriton is (usually) an expensive product. Unlike with thyroid medicines, the cheaper generic products seem fine. :-)

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I am absolutely no expert on anything and especially not hyperthyroidism.

The issue with carbimazole seems to be how it works. What it does is prevent your thyroid from manufacturing thyroid hormone. But you already have a high level in your blood, and lots stored in your thyroid. Even if the carbimazole worked instantly, it would take some time, possibly weeks, for the thyroid hormone levels to drop.

And if the carbimazole has stopped all or most thyroid hormone production, you can go from hyper to hypo very quickly when your stored thyroid hormone runs out.

Taking more carbimazole doesn't help once you are taking enough to suppress thyroid hormone production in your body. I have no idea where that is as a dose for you - or anyone else - I am afraid.


Thanks, yes I see what you mean... Thanks for the answer... I much prefer being on 20mg of Carbi (obviously as severity of hives is lessened...Plus hate taking drugs anyway!)...

But just wondered if it was enough to block the thyroid from producing... But as you say everyone is different... I wonder if 20mg is enough?

Hmmmm! Thanks again Helvella :-)


Wild poppy I think , as I said earlier, that CARBIMAZOLEis great at what it is designed to do ... So ... Don't worry

yourself ! I was in a bad way and quickly around three weeks later started to feel

It was working. ..slowly each symptom reduced in strength .. I don't blame you for worrying .. That ! After all is exactly what Graves' disease makes you do !

Have strength and patience

... Rest as often as you can .. Only work or walk for small periods at a time . Rest is crucial .. Sleep is another story And not so easy to get

Personally I took an over the counter sleep aid

As I couldn't cope without sleep at night !

You'll do it !!

Be strong

Take charge of your own

body !

Your health is Your responsibility .. As your find out trying to get doctors to help you ..


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Madge, thank you!

Yes, I have found that already with doctors 4 years ago when it took them a year to diagnose me with coeliac disease... I took charge of myself them, and told them I had coeliac! They refused to believe me but eventually decided to humour me with a blood panel! Lo and behold... I was correct!

You're right, its hard not to worry! I think Stress got me here in the first place, its hard not to be stressed with Graves, oh the irony!!!

The sleep! Or lack of it! Yeah, I am struggling to go to sleep before 2am... Then other household members start slamming doors at 6.30am... So its a problem I have to address.

Thank you for your kind words... Just wondering, you are Euthyriod. So does this mean you are off Carbi I assume? May I ask what supplements you take? What do they say about likelihood of Graves kicking in again? I guess its down to that immunity?

Again, thanks for your help...

Kimmy :-)xx


I had very high hyperthyroidism and they wanted me to go on carbimazole, telling me that it would wipe out my immune system though. This wasnt an option for me. Cancer risk increased instead of hyperthyroidism doesn't make sense to me. They also told me it wasn't a cure, it just hid symptoms for a while. Again this doesnt make sense to me. I did use high nutrition, juicing carrots, apple and ginger, and drinking clean water to bring the levels down to normal in just 2 months (I wrote about it in February on this site). It included doubling the supplement that gives me 80 trace elements in a balanced way each day, (SpectraMaxx) fucoidan,( FuCoyDon) high vit C, selenium, vit B\s and magnesium. And not eating gluten (which I have strictly maintained.. Being a bit erratic I didnt keep it all up to the levels required and need to re-do a boost at the moment, but that is my foolishness.

Just be aware of the side effects of these drugs. At least my consultant did tell me the severe downsides of Carbimazole... but she was shocked when I didnt then rush to have it anyway. All disease is caused by a combination of toxins and lack of nutrients needed by the body to keep itself healthy in varying degrees. We notice it more as we get older, and it is impossible to get from a basic diet anymore. Do some research, an op, radiation or drugs arent the only answer.


You said it Sedum ... 💐

Take a bow !



Thanks Sedum :-)

Did you get diagnosed with Graves? Or any other conditions?

I am wondering if perhaps having the antibodies creates a different situation?

I am juicing also, most days or least 5 out of seven... I also take a high quality food grade Selenium at high doses.. And will start Magnesium soon... And Chinese herbs.

I absolutely detest taking the Carbimazole... But my levels were so high, and heart rate dangerously high... That I worried not to take them...

What do you mean cancer risk? I did not know that Carbimazole wiped out the immune system?? Thats scary?

I agree that all conditions are caused by toxicity and deficiency... I am coeliac so quite likely am deficient. And 43... so probably toxic! Although, I have been gluten and dairy free for years, and vegetarian (but pesticides?)... I recently introduced cheese into my diet, and have been on a cheese fest for 6 months. But that has gone too!

Are you in the UK? Did they agree to monitor you if you refused drugs?

Perhaps its time for me to find a functional doctor!

Thanks for your reply, I have been struggling a bit today emotionally... You came just in time!

Kimmy :-)



Yes I am in Bristol UK. Normal Gp but she knows I don't do drugs and is very helpful. Tests were useful. I learned I had a problem then I researched a lot. The Sisel nutrition was a phenomenal base that I was already taking, but clearly not in big enough doses. My hyper levels were apparently very high too..43? The consultant couldn't handle that I lowered the high levels nutritionally to normal (22) and was almost angry. I really think SpectraMaxx is key. I took a double dose each balanced and totally bioavailable. I have never had success at cherry picking nutrients because they all need other nutrients to work and it is too complicated. A strong base then topping up with a couple when I read and understand why I might need a bit extra is how I work.

I have non coeliac gluten sensitivity, and take it seriously. It seems to affect my thyroid and my brain/nerves.

I didnt cure anything. I gave my body the nutrients it had exhausted in the amounts it needed and the body mended the problem.

Cancer.. is when the immune system doesn't have the capacity any longer to deal with the cancer cells each of us is bombarded with daily. The system has become deficient or too toxic and overloaded. Of course a dose of a strong drug isn't going to help it stay strong. This is why chemo and radiation seem barbaric to me, equivalent to the doctors bloodletting people until they died in the past.

All drugs have negative side effects and have to be dealt with the liver, and while they may seem to deal with the symptoms short term they are also toxic and slow the body being able to deal with things itself. Health = a healthy immune system. There is a case for a drug in an acute situation/emergency, short term. But I don't believe hyperthyroidism is due to a lack of Carbimazole anymore than cancer is due to a lack of radiation and chemo.

To learn a bit more about a nutritional approach I recommend going to one of Phillip Days talks. He is on tour in the UK at the moment. A researcher who tells it as it is and supports us helping ourselves.

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I like the sound of what you've achieved Sedum ... whilst on this site I gleaned a lot of very useful information from others with the same condition as mine ... Graves' disease.. I was in a dreadful state a year ago .

I started to take


B12 and

B Complex this combination of Bs gave me back some of the energy

that I was badly lacking ... and believe me they work

D3 helps with iron

Magnesium helps with sleep and other issues

Selenium helps immune systemh

Iron and

Vitamin K helps with iron



Vit C which helps if iron constipates you

The important one for me......

ACIDOPHILUS 20 billion

IVe been taking all of these for a year with the intention of boosting my immune system... that's why I believe, I'm Euthroid now.

and I continue to take them so that my Immune system stops annoying

my very healthy thyroid's not my thyroid to blame for my illness .. it's a wonky immune system.....therefore it made sense to me to fix that first..

so far it's worked.. I will not consider RAI or Surgery as the thought of cutting out of my body a perfectly healthy gland is horrifying ... that and the

fact that I will have to take a drug for the rest of my life is not an option I want to have ... several female members of my family have had this disease and some have no thyroid .. and I can assure you that for them is a downward spiral health wise .... never being able to reach a satisfactory level.

I'd much rather learn to control my thyroid by learning to feel and understand if and when my immune system is having a bad effect on it .

I believe it is possible to do that..



Awesome Madge...

I made friends with a lady on a forum last night, she also 'cured' her HYPER in a year... She started on Carbi, was only on it for 2 months, weaned herself off, did nutritional and supplements... She is Euthyroid.... Docs hated it!! Interestingly, they told her she had Graves... On second testing with a private functional doc, they tried an iodine loading test which confirmed that she had too much Iodine in her system! (She had supplemented through colloidal generic mineral) Her antibodies were not high enough for a Graves positive... Needless to say, she is 95 percent better, she is just building up her muscles again having been bedridden for a year with it... I know how that feels!

So, you know... there is more than one way to slay the beast... I understand why people trust doctors... I don't trust them AT ALL after my coeliac experiences with them... And even so, they managed to get me onto Carbimazole...

Its the first drug I have taken in YEARS. I don't even take headache tablets! I don't know why I listened, well, I do I guess... I was very ill and felt really scared as my heart was out of control...

All of the consultants were rude/annoyed with me, as I hadn't taken the heart meds!! I took just the Carbi! And then, one of them said to me, "you're one of those, aren't you?' When I asked what he meant, he said "Well, I can see that you don't want your medicine, you're someone that thinks they can do it another way, naturally or some ridiculous notion" (laughing at me) " you need to take the drugs or you'll be back in a critical condition, you're at high risk of a stroke or heart attack"..... I still didn't take heart meds, as my liver ached and I felt very unwell when I took them... I took it easy instead...and figured at least one drug less was better than nothing...

Anyway, I am rambling on, it's so nice to find people to talk to about it... think my hubby has had enough of it!!

Big hugs :-) xx

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Yep ! I always say ...

There's more than one way to skin a cat !

I think your phrase is better ! 🌸

Youre in the right frame of mind ... So keep at it !

And you can help others too by sharing your advice ...

It's wonderful that we pick up so much info along the way.... To benefit all ...

I'm no expert .. And some may think I'm mad trying these supplements but I read a great deal and researched them all before taking ... I know for sure my dr would not have told me to take them .. In diagnosing me he said

That I could just have the RAI .. And that would make me hypo .. Which is easy , as I just need to take a pill every day !!!!! 🙀🙀🙀

I also take Motherwort and bugle weed liquids ... And it greatly reduced the feeling of anxiety .... Google

Thyroid / L Carnitine

That is a natural substitute for Carbimazole ....

And it certainly makes me feel better

I used that to wean myself

off Carbimazole !

I'm certainly enjoying

Not having all the terrible symptoms I had with Graves a year ago ...

And hope you will too very soon ...

Oh ! And the bit about

3 consultants saying our problem is not related to Stress !!

Bonkers !!!



Thanks Madge... Fantastic! L Carnitine...I have read about that! What was your T4 when you started to wean off Carbi? Did it go down a lot?

I am on half dose now (20mg)... might leave it like that for another couple of weeks at least...

May I ask, do you exercise... I know I have ti be patient, but I'm desperate to start again! Keeps me sane, if nothing else!!

And, yes utterly bonkers!! Can you believe it... What a load of <bleeeep>!!

Again, thanks for being there... So many lovely people on this planet <3 And keep up the fantastic healing :-) wow !

Kimmy xx



Thank you for your detailed response...

I am a follower of Philip Day already! I have all his books!! Ok, the cancer bit I know, I actually thought you meant there was a known link between Carbimazole and similar to causing cancer directly... I see what you mean now!

I am so pleased to hear that you have treated yourself naturally, I am planning to come off Carbimazole as soon as my supplements come in... I hoping to treat myself naturally too. My HYPER levels are also very high at 51...

Yikes! I am with you on the drugs etc, chemo & radiation seem futile to me... I appreciate the names of the supplements, I will be looking into them... Am also looking for a functional doctor to help and have had some great advice...

Did you say earlier you have/had Graves?

I think its wonderful that you have gotten your thyroid levels down with nutrition, it says EVERYTHING! Do you cut sugar and dairy?

I am juicing everyday, taking food grade Selenium, Magnesium is on the way... And I have some Chinese herbs... May I ask, does Spectramaxx have iodine in it?

(I am already into the alternative, as I am studying Japanese Integrated Medicine)

Thank you for all your help, its great to see someone do the natural path, and you have given me the boost I needed... I have felt a bit disappointed and disillusioned that this has happened to me... I think the last year of Marital stress has finally done it tbh. Although 3 consultants have categorically stated that stress has no part to play in Hyperthyroidism!!! Says it all. Hospitals have their place, but in an emergency situation as you said.

I am weening myself of Carbimazole, down to half dose, and will continue...

Just your opinion, but do you believe dairy would impact on this?? When I was diagnosed with coeliac, I cut dairy as I couldn't digest (4years ago)... 6 months ago, I reintroduced, and began a cheese fest! Definitely overate on cheese! I don't think this caused anything, but I do think that so much cheese (all of a sudden) may have compromised my thyroid, and there seems to be some evidence of it impacting thyroid... Hmmm...

Thanks Sedum, you've been an angel, appreciate your help x


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