Hi,

Did your doctor want to refer you to endocrinology? There are a lot of different thyroid tests and results for say T3 as opposed to Free T3 can be interpreted different ways. Also just because a GP thinks your other levels are normal doesn't mean an endocrinologist would agree. Lab ranges are usually above what an endo wants to see which is typically a TSH between 1-2.

There is synthetic T3 called cytomel. When added to Synthroid Or other T4 replacement it allows a little more flexibility over Armour where the ratio of T3-T4 is fixed. This can be a good option for some. I have taken it for over 13 years in addition to the standard T4 treatment which left me still exhausted and not myself even with "normal" levels. The addition of a tiny amount made a huge difference in my well-being. It was like flipping a switch and getting the old me back from before my post-baby thyroid crash.

When in doubt consult the specialist! I hope you find answers soon.