I have been on Levothyroxine 150mcrg for years and am making the switch to NDT finally! My endo told me to stop taking levo and just go straight to 120mg (two tablets) of NDT at once. I am happy to see how I go, however I am little worried about my low iron levels as I hear this may cause complications. My ferritin is 9, but haemoglobine levels are good. Do you think this will be an issue? Also, from your experience, would you go ahead and switch at once or do it more gradually? Thanks a lot!