In July 15 began treatment for overactive thyroid . Now everything is perfect on 20 neomercazole and 25mg eltroxin. Feeling great. Endo now tells me I must have radioactive iodine treatment in May. Really scares me . It seems to be a drastic measure. It will be so difficult as I work alone and I have 10 dogs , some show dogs needing serious grooming weekly that only I can do . Is there an alternative ? He says prolonged use of neomercazole damages immune system . Please help I need more info before making up my mind or getting a second opinion from different Endo.