Just got blood work today - my free t3 is 4.2. my tsh is .48. my free t4 is .5. i started taking liothyronine 2 months ago. what does it mean?

A lot of T3 (liothyronine): Hi. By most lab normal ranges, that would be a slightly suppressed TSH, a frankly low free T4, and a free T3 (liothyronine) near the upper end of the normal range. Interpretation: You're supplying enough T3 (liothyronine) for your body to think it is a little too much, and suppress TSH secretion. The suppressed TSH reduces T4 output from the thyroid, so your free T4 is low. I doubt it's harmful to you; you could back off T3 (liothyronine).