The term Tonic refers to estradiol valerate tablets, which need to be taken for 21 consecutive days in the treatment of establishing an artificial menstrual cycle, and the treatment cycle needs to be decided according to the situation. Estradiol valerate tablets are estrogenic drugs that can be used in combination with progestins such as progesterone to establish an artificial menstrual cycle, mainly to improve the body’s lack of estrogen and other conditions. Usually, patients should first use estradiol valerate for 21 consecutive days, and thereafter add progesterone and other progestogens to promote menstruation and establish an artificial menstrual cycle. Due to the large variation between individuals, the specific drug dosage, as well as the dosing cycle should be guided by the clinician. It is important to note that missed doses of hormonal drugs may cause vaginal bleeding, so patients should take the drugs on time as prescribed by the doctor.