Thyroid UK
87,519 members102,231 posts

RAI agreed but now unsure- advice needed

Hello all, I'm a 31 year old man, and I just agreed yesterday to RAI in a fortnight, but am having second thoughts based on potential side effects of taking thyroxine forever, as well as the risks of RAI.

I was diagnosed as overactive thyroid c. 3 and a half years ago (at a similar age to my Dad when he was diagnosed) and put on 40mg Carbimazole which was gradually reduced down to 5mg until I came off the meds about a year ago, so after 2 years of use. It only took about a month for my levels to shoot back up again though and I was back on Carbimazole. A few months ago the 5mg made me underactive slightly, so my dose was reduced to 5mg every other day.

I'm torn though as I keep being told how RAI is safe, etc, but should I be trying to come off Carbimazole for a second time? That said, if it didn't work the first time, isn't it quite likely that my thyroid levels will shoot up again at some point down the line? Even if it isn't for some time? If so I'd rather get it zapped as the overactive symptoms I had for years were horrid, and also Carbimazole use seems to have ended up with me having recurring cold sores. This is having only ever had a handful in my entire life- I'm on my second of 2015 already!

I'm torn now between wanting to be rid of Carbimazole, the risks of RAI, and the concern over it potentially coming back if I was to try and be weaned off the meds again. Plus liek I said, recurrign cold sores aren't the most enjoyable side effect...

All thoughts really appreciated!


15 Replies

It's a pity that you attribute the cold sores to Carbimazole because otherwise I would be thinking why not stay on that low dose for as long as possible? Some people stay on it for decades. Do you have other unpleasant side effects? I was overactive and given Carbimazole but unlike you, could never get settled on the right dose. In the end I had a Thyroidectomy and have struggled ever since. I would not recommend destroying your thyroid unless absolutely necessary. Could you try some natural methods for defeating the cold sores? I suppose you use Zovirax? I also suffer from them, usually when my body is on a low. I was just in hospital with appendicitis and got one then. Maybe if you could boost your immune system, it would help.

Sorry if this is not what you want to hear but think hard before zapping your thyroid. It is just as difficult without it, in my experience.

1 like

Thanks for your thoughts- I do feel a bit trapped by the decision to be honest. I've always been very healthy and rarely sick (even with the overactive thyroid I've not had a sick day at work in 4 years!). But in the last few years on Carbimazole I've been a lot more run down and prone to colds/bugs as well as the cold sore. Other than that, to be honest I've been pretty symptom free, and it definitely beats the edgy rage of being overactive!

I do still have a pretty good immune system, as I exercise daily and eat very healthily from scratch, including a supplement as I'm vegetarian and just want to make sure that my diet isn't lackign in any areas.

I must say I'm terrified at the idea of being hypo from here on out- I've alwasy been full of get up and go in my adult life, so the thought of feeling listless is enoguh to put me off.

As I said, I feel very cornered by this at the moment as I already gave the thumbs up to the RAI for the 27th. I guess the biggest problem is that doctors never have the time to really go through the ins and outs of it all with you! After all, it's "just" an overactive thyroid and they treat zapping it as so incredibly routine, in fact never mentioning any problems with finding the right dose of Thyroxine replacement afterwards


If veggie and getting cold sores, make sure you are getting enough Lysine and not too much Arginine.


Hi JamieR, the following link offers an alternative:

You'll need to scroll down to the hyper section.


Hi Jamie, I had RAI & the relief of being free of symptoms of overactive was immense. I did go underactive & take Levothyroxine now, with a few adjustments to dosage I have been stable for a year now. I did get my bloods checked every 4 weeks but now it is every 6/8 weeks. From what I have read on here it is not for everyone, if I had been a member on here before having RAI I would have refused it because of what I had read. For me it was definitely the right thing to do.


This is the problem dusty2- I get so many positives AND negatives from people who've had the treatment. My Dad hasn't had any problems at all in my lifetime, to the extent that he thinks I'm makign a big fuss out of nothing. As if the whole thing is as routine as having a tooth pulled!

Out of interest- does anyone know that IF you bounce back after being Carbimazole and weaned off (as I said it was aroudn 2 years), does that mean that it is likely to happen every time? In other words is worth trying again, or am I just one of the people with a thryoid that doesn't "reset" as it's meant to?

1 like

I was diagnosed with graves disease in 2000. I was on carbimazole and beta blockers at first then carbimazole at 40mcg then block and replace...stop drugs...remission then flare up...on drugs then off drugs...this cycle continued until 2010 when I eventually had RIT. I didn't want it as I knew I'd go hypo.

I'm now 3 stone heavier than I should be and the doctor days I'm Ok.

I wish there was another alternative to zapping the thyroid as I was much happier when I was hyper!


Hi, I'm in remission from Graves at the moment - stopped my block and replace in November 2013 and fingers crossed have been fine since. I was told - twice - that should I relapse I would be given RAI and I told them - twice- that I didn't want it. I don't want it because I don't want to take the chance that I may end up hypoactive and end up having difficulty getting the correct dose of levo to keep me feeling well. I began to worry about it and worrying is not good for Graves people so I went to see my GP and was told that the hospital can neither force me to have RAI or refuse to treat me if I say no.

If you read Dr Anthony Toft's little book Thyroid Disorders - about £5 or so from Amazon - you will see that you can stay on Carbimazole or Carbimazole and thyroxine for the longer term.

I've been reading Amy Myers' book The Autoimmune System - all about curing yourself by healing you gut and auroimmune system. It sounds quite complicated - although I haven't actually reached the diet yet but basically she says she has cured people by curing their 'leaky gut'. I was quite surprised to see that cold sores / herpes simplex got a mention too. Unfortunately I'm reading the book on my Kindle and I can't get myself back to where she talks about cold sores :(

So this is a kind of roundabout way of saying have you tried a gluten free diet? I would want to have another try on antithyroid drugs, it would be worth going gluten free diet and seeing if that helped calm down your immune system. There are people out there who have had RAI and are fine but quite a few people come on here and say they regret killing off their thyroid.

You haven't said whether or not you are hyper because of Graves, if you are you will still have Graves antibodies after RAI - you just won't have a thyroid for them to attack.

It's a very hard decision to make but I wouldn't get pushed into it if I were you. Read as much as you can about your options there are a lot of books around - start with Dr Toft's book - he is part of the 'establishment' so hopefully your doctors will take note if you quote him. Some people have been on carb for extended periods of time.

Obviously some people have no option but to have RAI ir a thyroidectomy - people who are unable to tolerate Carbimazole or PTU or who have thyroid cancer but I know I would definitely want to have a second round of Carbimazole should I relapse.

Good luck and excuse the ramble.


Jamie, Cancel the RAI appointment and buy yourself some time to consider and think it through more thoroughly. RAI can be rescheduled if you decide it is the better option. Do you know whether you have Graves antibodies? If you do, permanent remission off Carbimazole is unlikely.

Cold sores are caused by herpes virus and once you have the virus cold sores will recur periodically and more frequently when you are stressed, run down or ill. I've had them all of my life but I've had very few since I've been hypothyroid and optimally medicated and vitamin deficiencies corrected.

Hyperthyroidism can burn your vitamins faster than you can replace them so you may be prone to cold sores, bugs and colds because your vitamins and minerals are low rather than Carbimazole being the culprit. 1-2,000mg vitamin C daily will boost your immune system. Are your ferritin, vitamin D, B12 and folate levels good? If you don't know, have them checked by your GP or privately via Blue Horizon or Genova. Post the results in a new question for advice and don't accept the GP saying 'normal' or 'fine', they usually aren't. Supplementing if levels are low will improve overall health, often within 8 weeks. Vegetarians need to supplement B12 as it is only obtained from eating meat, fish and eggs and isn't available from plant foods.

If you optimise vits and mins and have less colds, sores and bugs you may want to remain on a very low maintenance dose of Carbimazole every few days rather than cook your thyroid. If supplementing makes no difference then RAI may be the right thing for you.

I'm not anti-RAI, I've had it twice for thyCa with no adverse effects, but I don't like to see people making irrevocable decisions when they have serious doubts. My sister had RAI because of Graves and TED. She was badly advised because TED has worsened and she isn't happy about it, but she doesn't regret not having a thyroid and has been stable and happy on 100mcg Levothyroxine for more than 3 years, taking up running a year ago and working full time with a busy social life.

If you search RAI via the Search HealthUnlocked box you'll find hundreds of posts which may help you decide.


Thanks Clutter/Fruitandnutcase. I've never been tested for Graves antibodies actually- unless it was part of the full blood screening that they've done at various points and as it was negative never mentioned it? Good old NHS!

I do take daily effervescent multivitamins plus I have a very healthy diet, with a lot of fruit, veg and pulses, and seeing as my thyroid has been relatively well controlled for a good while, I'm as sure as I can be that deficiencies aren't an issue.

I'm just very unsure again now, having been so fed up of popping carbimazole that the RAI sounded like a great idea. I felt horrid when I was off the Carbimazole the first time and I went extremely overactive again, so I'm slightly anxious for that to not happen again. But that said, all I seem to read on forums, etc is negative feelings post RAI. How much of this is simply because peopel are more likely to post somethign negative than a positive experience, I don't know, but I keep swaying from pro to anti RAI...


1 like

Jamie, Have you been told that you can become very hyper after RAI for a few months as the thyroid dies off and dumps hormone? Within a year of RAI you'll be hypothyroid and popping Levothyroxine daily.

You don't know whether you have vitamin/mineral deficiencies or sub optimal levels unless you test. If you are low a multivit will be inadequate. As I said, hypers burn through vits/mins.

Postpone your appt to give yourself time to research and think it over without the pressure of a deadline looming.

1 like

You must test B12 & folate if you have been on a vegetarian diet for a long time.

Those with B12 deficiency also those with pernicious anaemia have difficulty with stomach absorption, so by mouth doesn't work & that's why they have injections.

Look up Dr Chandy. J


This is the worst-case scenario and the person, because of her experiences, has a Petition before the Scottish Parliament. I doubt whether things were explained clearly to you and should be as it is a big decision to make and, as Clutter says, she is fine but she had to have T3 added and some doctors will not prescribe it. I wonder once the op is over if you ever see the doctor again.

This is what Dr Toft, who was President of the British Thyroid Association says:-

5 Patients with hyperthyroidism often ask for advice on drug treatment versus radioiodine therapy. Can you summarise the pros and cons of each?

The three treatments for hyperthyroidism of Graves’ disease – antithyroid drugs, iodine-131 and surgery – are effective but none is perfect.4

Iodine-131 will almost certainly cause hypothyroidism, usually within the first year of treatment, as will surgery, given the move towards total rather than subtotal thyroidectomy.

There is no consensus among endocrinologists about the correct dose of thyroid hormone replacement so patients may prefer to opt for long-term treatment with carbimazole. Standard practice is that carbimazole is given for 18 months in those destined to have just one episode of hyperthyroidism lasting a few months.

But there’s no reason why carbimazole shouldn’t be used for many years in those who do relapse. Any adverse effects such as urticarial rash or agranulocytosis will have occurred within a few weeks of starting the first course.

Iodine-131 treatment for toxic multinodular goitre is the most appropriate choice as hypothyroidism is uncommon. Surgery would be reserved for those with very large goitres and mediastinal compression.

Once hyperthyroidism has developed in a patient with a multinodular goitre, it will not remit and any antithyroid therapy would have to be lifelong.


If you wish to have a copy of the whole article, email and she will send you it, probably on Monday.


I have Graves, was on Block and Replace for 18mths, stopped, relapsed within the month (prob didnt go into remission at all) Back on Carb alone, titrated down over about 2 yrs, to 2.5mg four times a week. Have been off the Carb for approx 7 weeks and apparently (according to levels) in remission. I actually feel like I am slightly hypo (maybe my thyroid has given up the ghost!) but will see how things settle and get levels tested in a few weeks.

If I had a choice between cold sores (which I suffer from when Im stressed) and going hypo, I would not choose the latter!

If there are any signs that you have Thyroid Eye Disease, dont have RAI!

I would have as many things tested as possible, before you decide on what to do.

Was surgery suggested?


I'm wondering about RAI as well. I'm off Carbimazole at the moment, have been since November last year. But i'm due at the hospital on tuesday & I've got a horible feeling that my levels will be up again. This is my second time of being on Carbimazole in 5 years. So I'm not sure if I'm looking for symptoms, but shaking was my first symptom that took me to the doc & it was the reason I knew my levels were up again. I am not shaking as much as I have, but I don't feel right. But each time I've been at the hospital this time, I've been told that I need to get RAI. I've always said I'm not interested and I want give my body a chance to see how this course would work. I don't want to be on thyroxine for the rest of my life, nor do I want to keep having to give blood for tests, I don't want my enegry levels & weight to be mucked up all over again, cos to be honest I've not got them sorted since i've been back on the pills. Needless to say I'm dreading Tuesday. Do I have a choice? Can I say no to RAI? What does it mean? they've told me I can't be on Carbimazole long term. is there any natural supplements? I know i'm clutching at straws, but I'm really worried.


You may also like...