Hi Mere, I'm new on here and was just skimming through your diary. I've got an underactive thyroid too which was diagnosed about 5 years ago now. I'm on a daily dose of 125mcg of Levothyroxine. I thought I was tired all the time because I was 47 and chasing round after a lively 5 year old. I also found it really hard to lose weight all the time which made dieting soul destroying. Sadly, the weight didn't start falling off once I got on the tablets so am on here to try and finally shift it.