I'm 43 & my last period was back in March, before that they were pretty regular. My Synthroid has been increase 3 times now, i am now taking 75mcg's, started off on 25 (last summer) Also my frees, while in the normal range ,are in the lower end, in fact so much that i convinced my pcp to put me on Cytomel in a baby dose of 5 mcg's, it has been a week since the increase & while i do feel 75% better (was feeling awful with some hypo symptoms before) still nothing. someone said that if your Free T3's & T4's are low, or not at midpoint of the range, that can throw off your cycle (a better term for lack of periods) I am miserable! :confused: I had a pregnancy test, negative, My next birthday is in a couple months & i'm probably in perimenopause (according to my gyn dr) I think the cytomel is slowly helping. Is there any other female going through this or has gone through it? I have a script for labwork but I want to wait at least 6 weeks due to the recent med adjustment & addition.