Why does one need to take neo carbimazole and levothyroxine at the same time?

That is odd I must say. One is going to contradict the other, as you have now found out by your latest blood tests. The neo carbimazole has made you go hypo, so really you should only be taking the Levo. Common sense would dictate that wouldn't it. I'm not a Doctor don't get me wrong, but I suffer from Hashimotos, and I'm under medicated as I need T3, but he won't give it to me! Whats more I also live in France too, so I understand where your coming from with that.

My Doctor doesn't explain anything to me either, so I pay for my blood tests, and read them myself. How much Levo are you taking? I'm on 100mg per day. Have you been tested for all your vitamins as well? especially Vitamin D, Folate, Folic, and all your B's?

If I was you, but I'm not, I would stop the Carb, and just take the Levo for the time being, wait for 4 - 6 weeks, then pay (it only cost about 30€) or go back to your Doctor for another prescription, and take it from there. Your levels should be reading within the upper 2/3 of the lab parameters.

Call and ask for an explanation any time you question something.

If you cannot get a straight answer, time to find another doctor.

So someone on yahoo gives you medical advice and you take it. Stupid runs deep in you

I only take levothyroxine and my checkups have been fine for years.