TSH suppression therapy after surgery for differentiated thyroid cancer refers to the application of thyroid hormones after surgery to suppress TSH at or below the low limit of normal or even undetectable levels, in order to replenish the thyroid hormones that patients lack on the one hand, and to inhibit the growth of thyroid cancer cells on the other. the preferred drug for TSH suppression therapy is L-T4 oral preparation (levothyroxine, trade name Euthyrox or Retis). Generally, after discharge from the hospital, patients start taking Eugenol, often starting with 1 to 2 tablets, rechecking T3T4 every month and adjusting the dose according to the results until the index reaches the expected standard. Subsequent reviews can be done every 3 to 6 months.