The active ingredient of Eugenol is levothyroxine (L-T4), which has a clear content and good efficacy, and is mainly used as a supplement and replacement therapy for hypothyroidism caused by various reasons. However, because clinicians and patients do not know enough about Eugenol and do not know how to take it, they often mistakenly think that Eugenol is “ineffective”, resulting in poor control of the disease. Due to the increasing prevalence of thyroid disease, doctors are using Eugenol more and more frequently. Many people ask why the instructions recommend taking Eugenol in the morning on an empty stomach. Sometimes, even though we think the dose of Eugenol is sufficient, the patient’s TSH level is not effectively controlled? In the end, it is because we do not know enough about Eugenol. In fact, many reasons can affect the absorption of Eugenol and cause its drug concentration to decrease. As we all know, for papillary thyroid cancer, TSH suppression therapy is a very important tool. However, clinically, it is found that some patients have taken a lot of Eugenol, but the TSH level is still not well suppressed. Is it related to the lack of deiodinase in some patients’ bodies, as other experts said? If we find clinically that we think the amount of Eugenol taken is sufficient, but TSH is still not suppressed, we have to ask about a few points. 1, the source of eugenol: some patients’ eugenol is bought from pharmacies, but we can’t rule out the possibility that pharmacies will have fake drugs. 2.If we can be sure that the eugenol is from a regular hospital, we need to further ask the patient whether the time of taking the medication is correct; whether the compliance of taking the medication is good; whether there is milk, soy milk, etc. immediately after taking the medication, and whether there are calcium tablets, etc., because these can affect the absorption of eugenol. 3. Ask whether there are gastrointestinal diseases, whether you are taking proton pump inhibitors, etc.; whether there are signs of lactose intolerance, such as intolerance to drinking milk. 4. If all of the above are ruled out, then consider other factors: such as thyroid hormone resistance syndrome, more rarely with deiodinase abnormalities; more rarely with a pituitary gland that simply responds poorly to T3 as the cause. For the surgeon, the first thing to do is to rule out factors affecting the absorption of eugenol, after which you can try to increase the dose of the drug or replace part of the L-T4 with thyroid tablets to be taken, since thyroid tablets contain T3 components, and then recheck the thyroid function. If TSH is suppressed, it is possible that this is due to deiodinase abnormalities. However, it is important to note that deiodinase abnormalities only occur in patients after total thyroidectomy, so they are not common. A few tips on taking medication for your study and correction. 1.Discern the authenticity of Eugenol, inform patients to buy it in the regular hospital, do not lose a lot because of small. 2, the correct storage before a patient with hypothyroidism long-term treatment of eugenol, the disease is well controlled, but once the summer its thyroid function indicators fluctuate greatly. After repeated inquiries, it was discovered that he did not put the medication in the refrigerator, but put it in his bedroom, and the high temperature caused the medication to fail and deteriorate. Therefore, we should inform the patient to store the medication according to the instructions: refrigerated below 25°C. Because of its long half-life (about 7 days), it can be taken only once a day to obtain a stable blood concentration. Because the absorption of Eugenol may be affected by taking it with food, the recommended time to take Eugenol is early in the morning on an empty stomach if possible, with breakfast 30 minutes after taking the medication. This is because taking it with food may interfere with the absorption of Eugenol. If the dose of the drug is slightly larger, it can also be taken in two doses, early in the morning on an empty stomach before bedtime (3 hours after dinner). Some people may ask: Why is bedtime dosing not routinely recommended? Because taking the medication early in the morning is more in line with the circadian rhythmical changes of thyroid hormones. Generally speaking, it peaks after 5-6 hours of taking eugenol, so if you take it at night and it peaks at around 3:00 am, your heart will be so excited that it will make your heart skip a beat, so do you still want to sleep happily? But in everyday life, compliance with the medication is also an issue that needs to be considered. Nowadays, many young people wake up very late, but need to solve breakfast before going to work, in this case, taking the medication before bedtime may be the best choice. Many studies have found that some diets may affect the absorption of eugenol, such as grapefruit, soy, strong coffee, milk and high-fiber diets, so avoid taking it with such foods. After informing him about the effect of soy milk on the drug, he never drank it in the morning again and his thyroid function indicators were normalized. This is why Prof. Guan prompted to ask the patient if he drank soy milk and milk after taking Eugenol. Tips: Take Eugenol with plain water and do not eat any food within half an hour. Tips: Eugenol should be taken 4-5h before taking Eugenol and Clofibrate. Drugs containing aluminum, iron and calcium: such as gastric mucosal protector aluminum thioglycollate, antacid aluminum hydroxide, calcium tablets, etc. can complex with L-T4 in the intestinal tract and prevent its absorption. Tips: Eugenol should be taken at least 2h before taking the above drugs. Drugs affecting the PH value of gastric juice: H2 receptor blockers and proton pump inhibitors affect the PH value by inhibiting gastric acid secretion, preventing its absorption.Tips: Eugenol should be taken at least 4h before taking the above drugs. 6.Diseases affecting the absorption of Eugenol such as celiac disease, liver cirrhosis, gastric acid deficiency and other absorption disorder syndromes. In addition, some people have lactose intolerance, such as milk drinking intolerance, etc.: because Eugenol contains lactose, these patients may be intolerant to Eugenol. 7. drugs affecting the clearance of eugenol Since L-T4 is mainly metabolized in the liver, any drugs with liver enzyme-inducing effects, such as barbiturates, phenytoin sodium, carbamazepine, rifampin, etc., will accelerate the metabolism of L-T4 and increase liver clearance, resulting in a shorter duration of action in the body and a decrease in blood concentration. tips: patients taking these drugs at the same time will need to increase the dosage of eugenol. It generally takes 4-6 weeks to replenish thyroid hormones and re-establish the balance of the hypothalamic-pituitary-thyroid axis. Therefore, at the beginning of treatment, the relevant hormone indicators are measured every 4-6 weeks, and then the dosage of Eugenol is adjusted according to the test results until the treatment goal is reached. After the treatment target is reached, the relevant hormone indexes need to be rechecked every 6-12 months. If the treatment does not reach the target, the reasons should be carefully searched, such as whether the patient is informed of the correct time and precautions to take the medication, and whether there are any conditions that affect the absorption of the medication, one by one.