**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 + T3 uptake (THBR) + thyroid-stimulating hormone (TSH) + thyroxine (T4)
Patient Preparation: Discontinue any supplements containing Biotin for 72 hours prior to specimen collection.