I've been on Levothyroxine now for two and a half months and I'm still feeling terrible. Started on 50mg and have been on 75mg now for two weeks. My initial TSH level was 6.1 and doc said next blood test was in the normal range (didn't ask what it was) but because I was still having symptoms he increased my dose. Apart from a temporary respite from my chronic constipation in the first weeks nothing much has changed. I still feel totally exhausted all day, sleeping badly, have no libido, feel weepy and depressed and very irritable. I've also been having terrible headaches since I started on the thyroxine and dizzy spells. I think I may have been underactive for some years but have been putting the symptoms down to the menopause (i'm 59) and prior to that work related stress. I'm due another blood test in about 6 weeks. Should I go back to the doctors or tough it out till next test. How long does it take to start to feel well?