Thyroid cancer is one of the common malignant tumors of endocrine system, accounting for 0.4% of all malignant tumors; the average incidence rate reported in foreign literature is 4/100,000-6/100,000. The incidence has been increasing in recent years, with an annual increase of 5% in the past 10 years. Thyroid cancer treatment is currently based on surgery, and patients who have undergone surgery still need further treatment, i.e. levothyroxine tablets (euthyroxine). There is clear evidence that taking Eugenol after thyroid cancer surgery has a good effect in preventing cancer recurrence. In the clinic, I often encounter some thyroid cancer patients who have undergone resection surgery and do not know how much Eugenol should be taken after surgery. How to take it? This is always a problem for patients. How much should be taken? Generally, it is recommended that patients with thyroid cancer should take Eugenol promptly after surgery. The initial dose is one tablet (50 mcg) per day; if the patient is older than 65 years old, or has coronary heart disease, or is a postmenopausal woman, or has other serious illness, the initial dose should be 1/4 to 1/2 tablet per day or even less, with slower increments and longer adjustment times. The final dose of Eugenol depends on the monitoring of serum thyroid stimulating hormone (TSH). Because the severity of the disease and the risk of side effects from taking Eugenol vary from patient to patient, the doctor will set different treatment goals, i.e., the range of TSH values to be achieved, taking into account the patient’s actual condition. According to this target, patients need to adjust the dosage of Eugenol until the target is reached. It is recommended that patients go to the hospital every 4 weeks or so to measure TSH, which is used to decide whether to increase or decrease the dosage of Eugenol; after reaching the target, the TSH is measured every 2-3 months within 1 year, every 3-6 months within 2 years, and every 6-12 months within 5 years to ensure that the TSH is maintained in the target range. How should I take it for best results? The best way to maintain a stable TSH level is to take it on an empty stomach before breakfast. If you miss a dose, you should take a double dose until the entire missed dose is made up. For example, if you missed a dose yesterday, take a double dose today and start taking it normally tomorrow; if you missed a dose the day before or yesterday, take a double dose today and tomorrow and start taking it normally the day after. And so on. In addition, certain special drugs or foods should be taken after sufficient time interval: 1 hour should be interval with vitamins and tonic products; 2 hours should be interval with foods or drugs containing iron and calcium; 4 hours should be interval with milk and legumes; 12 hours should be interval with lipid-lowering drugs. In this way, it is possible to ensure that a stable level of treatment can be achieved after taking Eugenol while its side effects can be minimized. For patients after thyroid cancer surgery, they should not only have the confidence to insist on taking the medication, but also have the correct way to take the medication, only then can they achieve satisfactory clinical results and reduce the possibility of cancer recurrence.