Most patients need to take Eugenol (also known as levothyroxine sodium tablets) after thyroid disease surgery, especially for thyroid cancer patients, they should take Eugenol strictly after surgery to prevent recurrence, however, most patients have great concerns about taking the medicine, thinking that Eugenol has great side effects and it is troublesome to take the medicine every day and wait, here is some knowledge about Eugenol for you. The difference between Eugenol and ordinary thyroxine tablets Ordinary thyroxine tablets are a mixture of T3 and T4, while Eugenol is a levothyroxine tablet, i.e. T4. The advantages of Eugenol are: (1) On the surface, because there are T3 and T4 in the human body at the same time, it seems reasonable to make tablets from a mixture of T3 and T4. But in fact, the majority of T3 in human body is converted from T4 (we note that T3 is more active than T4), therefore, patients with thyroid cancer take more Eugenol orally, which suppresses TSH, but does not increase much T3 in the body, but only T4, resulting in less side effects. (2) The price of Eugenol is not much more expensive, more than 30 yuan for 100 tablets, which I believe any family can afford. (3) Also, the T3 half-life is 24 hours, while T4 is 1 week. As long as you have studied mathematics, you know that the blood concentration obtained from taking euthyroxine is definitely more stable than that of ordinary thyroxine tablets (in the past, patients taking ordinary thyroxine tablets were generally taking it twice a day, and the patients were less compliant). Therefore, ordinary thyroxine tablets have now been eliminated. 2. Dosage and timing of benign and malignant oral euthyroxine (1) There are many patients with benign thyroid nodules who do not need surgery and always want to take drugs to control the growth of nodules. ATA points out that the routine application of thyroxine suppression therapy is not recommended for the treatment of benign thyroid nodules in areas with normal iodine intake, therefore, the best approach for these patients is to have an ultrasound examination once every six months. (2) Benign diseases such as nodular goiter should be treated with eugenol after surgery so that TSH is controlled in the middle to low 1/3 of the normal range, e.g., the normal reference value of TSH is 0.27-4.2, which is best between 1-2. The timing is determined by the TSH review results. Even if the surgery has little effect on TSH, it is best to take it for six months to a year to be able to inhibit the regeneration of nodules in the remaining thyroid tissue. For patients with subtotal thyroid excision, the duration may be longer, with the possibility of lifelong medication. (3) For malignant disease, oral eugenol is recommended by the 2011 NCCN guidelines at 2.11ug/KG/day to make TSH less than 0.1 (complete suppression), while the NCCN guidelines also emphasize the selection of the optimal amount of inhibitor according to the individual patient’s condition (heart, osteoporosis, hyperthyroidism toxicity) to make TSH slightly less than the low limit of normal or slightly above the low limit of normal. Of course, the amount of remaining thyroid tissue varies and so does the dose of eugenol required. In Europe and the United States, many thyroid cancers are completely excised, but in China, there is still a lot of residual thyroid tissue, so 2.11 may refer to the dose for patients with complete excision. Therefore, it is important to review the thyroid function and adjust the dose of Eugenol according to the thyroid function. If the dose is not relapsed after 5 years, you can consider reducing the dose at your discretion.