Thyroid UK
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Block and replace - Any experience


I'm hyper and I relapsed 3 months ago after 2 years. The first time, I simply took Carbimazole for 8 months.

This time Carbimazole works but is far less efficient. I just saw the endo and he told me that the only way to be fully cured is to do a block and replace for 6 months. I'll see him next month to start the treatment if I'm OK with it.

I don't know what to think as I remember reading awful testimonies about Block&Replace. Is it really more efficient? Well any experience welcome. I'm a little panicking as I'm self-employed and was always able to work while under Carbi. I'm wondering if I'm going to be able to work with Block&Replace.

Thanks a to all of you.

Take care.


9 Replies

I've been on b&r for 16 months and came off it 2 weeks ago. All going okay so far fingers crossed for remission. The only problem I had with b&r was finding the right balance of Levo. On 100mcg I was fine just put on some weight. We upped my dose to 125 for 3 months and I had dreadful panic attacks, stress feeling and palpitations. These all disappeared when we dropped my dose back to 100mcg. Other than that b&r is doable and works. Alex


Thanks for your reply. Were you able to work in a stressful and fast paced environment during this time? That's my problem I work in IT and I'm completely fine on Carbi but I don't think I could work on B&R. Nathalie.


Yes it's possible. I work in marketing for a large pharma company. I'm 40.


I think your Endo is possibly being a little optimistic saying B&R will fully cure you, he/she cannot know that for sure.

I did B&R for a while after many relapses spanning 30 years, didn't work for me, as Alex said it can be difficult to get the right doses, I just got fed up with the constant change in doses and having previously had a partial thyroid op it was unklikely I would be "cured" so I asked for RAI, result, job done.

Give B&R a try, you may get on really well, good luck.


As I said in my previous reply, I have a stressful job with long hours and it's difficult for me to deal with adjustments. I know my endo is way too optimistic. I relapsed 3 months ago after 2 years and Carbi is not as efficient as the first time but I was cured in 8 months the first time.


Im afraid, as you probably know, there is no 'cure' for Graves, just remission.

Personally, B&R didnt work for me, but Carbimazole did. Looking back maybe it was a dosing thing. My Endo was adament I was on the 'best' dose as my levels were good, but I never felt well and had lots of hypo symptoms.

B&R is usually done for 18 mths though, then stop all medication and see if you go into remission.

Give it a go, what can you lose *tongue firmly in cheek*. Maybe you could try for 6 months see how you go.


My endo wants to do it for 6 months only. Well, I think it's not for me. Thanks for your reply.


What is the alternative though?

Can I ask what negative things you have heard about B&R? I know one of the admin has been on it and has gone into remission so it obviously suits some people. Again, I think you need to get the Levo dose right and go by how you feel not your blood levels.


I didn't explain my situation. I was hyper for only a month before being put on Carbi. It's a relapse after 2 years of remission and I was tested privately every month during 2 years. My T4 were at 43 (9-19) and TSH suppressed when I started 15mg of Carbi mid-august. A week after, my T4 were at 20. Since then they have been at 23, 25, 20 so my GP changed to 20mg. I have no symptoms at all, my resting heat rate is between 55 and 63 - I do a lot of sport. So wanting to put me on B&R so fast after only 2 month and a half of treatment and without doing a blood test since I'm on 20mg is insane.


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