I've been taking 150mmg of Levothyroxine for over 20 years and want to replace taking this with desiccated thyroid. My nutritionist said as an MS sufferer '20 years' I would never get better as long as I continued taking Levothyroxine. My two question I have is a) how much desiccated thyroxine would I need to take and b) can I get this from my GP, if not how do I purchase this?

Any advice would be much appreciated.