1.What is Eugenol? Thyroid hormones refer to T4 and T3, and it is mainly T3 that plays a physiological role, and most of T4 also needs to be deiodinated into T3 in order to function. Naturally, both T3 and T4 can inhibit thyroid stimulating hormone secretion through negative feedback. The main component of Eugenol is T4, and taking Eugenol is equivalent to supplementing T4. 2. Why can Eugenol cure hypothyroidism? It is easy to understand that Eugenol is used for hypothyroidism, because hypothyroid patients do not synthesize enough thyroid hormone by themselves, and giving Eugenol is a replacement therapy, T4 is replenished, T4 is enough, T3 converted from T4 is also enough, then the body needs the physiological function of thyroid hormone. 3. Why can Eugenol also be used as an adjunct to anti-thyroid drugs? Hint: For hyperthyroidism treatment, Eugenol is used as an adjuvant to anti-thyroid medication rather than as a direct treatment for hyperthyroidism! There are currently 2 options for hyperthyroidism treatment: (1) Anti-thyroid medication alone, such as tapazole or propylthiol. (2) Anti-thyroid medication + Eugenol. As to why Eugenol can be used as an adjunct to the treatment of hyperthyroidism, it is important to mention the advantages and disadvantages of each of these two treatment options. The first option is better because the dosage of antithyroid drugs is less, but the possibility of hypothyroidism is higher. The second option can better avoid hypothyroidism and reduce the fluctuation of hormone levels, but the disadvantage is that the dosage of anti-thyroid drugs will be higher and the corresponding side effects will be more. 4. How should I use Eugenol? (1) Clinical situation: During the treatment of hyperthyroidism, hypothyroidism occurs when the anti-thyroid medication is slightly more, and hyperthyroidism occurs when the anti-thyroid medication is slightly less. In cases like this, which are more difficult to treat, anti-thyroid medication combined with euthyroidism can better balance the levels of thyroid hormones. (2) For hyperthyroid patients with proptosis or goiter, a small amount of Eugenol can also be given as appropriate. The purpose of this is to suppress TSH, as the patient’s thyroxine will gradually decrease when given anti-thyroid medication for hyperthyroidism, and then the suppression of TSH will gradually weaken, and an increase in TSH will aggravate proptosis or goiter. (3) It is logical to use eugenol for hypothyroidism. (4) Other indications for eugenol: non-toxic goiter, use for prevention of goiter recurrence after goiter removal, etc.