Hi could anyone on here possibly give me a definitive answer? I'm a man who had radio iodine treatment last September for Graves' disease. The treatment has made me hypo. I was put on Levo starting at 50mg last December but found the Levo has given me crippling insomnia. Despite telling my endo this my strength has been put up three monthly until I'm now on between 100mg or 125mg despite the quite debilitating insomnia (I now only sleep if I take sleeping tablets but they only work occasionally but if I don't take them I have very little sleep and then poor quality sleep) I found a GP in the UK would has prescribed me NDT (Naturethroid) as I thought the fillers in the Levo may be the problem. However the insomnia persists. I have read a huge amount of contradictory information regarding strengths so wondered if I am taking too much NDT? Some say 1 grain is 60mg of Levo others say that 1 grain is equivalent to 100mg of Levo. I was on 100mg of Levo and have been taking 1.5 grains of Naturethroid as according to the conversion website that is the equivalent of 100mg of Levo. I doing everything I can to normalise sleep. Any advice please?