Question: is tirosint t3 or t4?
Answer: Synthroid (levothyroxine sodium) and Tirosint (levothyroxine sodium) are synthetic compounds identical to T4 (levothyroxine) produced by the human thyroid gland used to treat hypothyroidism due to many causes (for example: thyroid removal, thyroid atrophy, functional T4 deficiency, radiation treatment of the thyroid, ...