Underactive Thyroid

I've been on thyroxine for so long now I can't remember how I felt when i was diagnosed but my son (43) was diagnosed last year and it's taken him several months to start to feel the benefit of the meds. Its a bit trial and error to get the dosage right for your needs.

When is your next blood test due? As others have said, it takes a while for the medication to kick in and doctors will generally err on the low side initially. After I started on it, my first blood test was after 3 months, then the dose was increased, another 3 months then again and now its stabilised and I'm tested every 6 months. So check when your GP said you had to be tested again - I certainly wouldn't want to wait longer than 3 months

It could take a while to get you on to the correct dose. Are you having regular blood tests?

I had/have an overactive thyroid which was pretty awful, was prescribed carbimazole which took about five weeks to make me feel better. Then I was told my thyroid level was now too low! So I am taking levothyroxine (sp ?) as well.

I think these drugs are quite slow to act, and they can have some funny side-effects, but we (well, I) would be in a mess without them.

I have been diagnosed for about a year and it takes a while to get the correct level of medication for you. You need regular blood tests and the dose can be adjusted accordingly.
It took me a couple of months to feel any different.