Hello Choosiesusie.If you are in the UK,you are probably not being given the correct meds.We don’t even test for reverse T3 .Levothyroxine is a synthetic ‘cure all’that doesn’t work for everyone(or possibly anyone).I was prescribed this medication in 2014 and the dose was eventually upped to 125ug in 2016.By then I could barely function.Lost eyebrow hair and eyelashes (gosh how I miss them ha ha)Most of all though I have more or less had permanent ‘brain fog’.The ranges for blood test results seem to change every few months.We were better off with the pig derived meds.
Anyhow,I decided to stop taking the meds in Jan 2017 and have lost more than 60lbs with FD and BSD.Brain fog still there though…think damage has been done😑😑
30 years seems a long time to be on these meds ‘you’ll lose weight ‘they say when first prescribed…..pants on fire eh??
If you’re not in UK you might be able to get ‘threonine’ prescribed alongside thyroxine..but if your blood test results are within’range’on just Thyroxine (whatever range they might be at the time)then you’re OK to go.NOT
Best Wishes.

I found it interesting to read these comments. I am in the U.S. and have been on thyroid medication for years now. I suffer from brain fog and memory problems and am constantly blaming it on other things. I have also lost eyelashes and a lot of hair from my head. It never occurred to me that my thyroid may be the reason but I am very doubtful that my doctor will up the dose of my medication. This could also be the reason for me having trouble losing weight but I have not been very good at dieting. I always start out okay but then lose motivation!! Oh, well!