FREE THYROID PROFILE Free T3 (FT3): Measures the level of active, unbound triiodothyronine, a crucial thyroid hormone Free T4 (FT4): Measures the level of active, unbound thyroxine, another essential thyroid hormone TSH (Thyroid-Stimulating Hormone): Produced by the pituitary gland, it signals the thyroid to make more or less T3 and T4 Price : 700/