**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.**
T3 is used to evaluate thyroid function. Triiodothyronine is a hormone produced by the thyroid gland and helps regulate how your body uses energy.
Patient Preparation: Discontinue any supplements containing Biotin for 72 hours prior to specimen collection.