**Note: All laboratory testing requires an authorizing physician. DHA Laboratory offers a patient direct program that partners you with an authorizing physician. If you have any additional questions regarding the availability of testing, please contact our laboratory by telephone or email.**
Free thyroxine index (FTI); T3 uptake (THBR); thyroid-stimulating hormone (TSH); thyroxine (T4); tri-iodothyronine (T3)
Patient Preparation: Discontinue any supplements containing Biotin for 72 hours prior to specimen collection.