Is there An optimal level for a free T3 Free T3 is the active form of thyroid hormone, whereas T4 is the storage form of thyroid hormone, which really has no active activities A normal free three range of 2.2–4.4 and when I am prescribing medication’s, I usually prefer to try and get the patient up around the middle area or 3.3 however everybody is individualized and some people may feel overstimulated at levels around 3.3 So optimal ranges aren’t really a thing it’s more. Where do you feel opti