Estradiol valerate tablets are a kind of estrogen, and there are many possible side effects after taking them, mainly in the following aspects: 1st, nausea, vomiting and other gastrointestinal discomfort may occur after using the drug; 2nd, headache, increased leucorrhea and breast pain may occur; 3rd, excessive hyperplasia of the endometrium may occur, accompanied by hormonal withdrawal bleeding; 4th, weight gain and change in libido may occur; 5th, long-term use may lead to an increased chance of breast cancer and endometrial cancer in women, and may also lead to liver and kidney damage. The use of valproate for a long period of time can lead to an increased chance of breast cancer and endometrial cancer in women, and can also lead to liver and kidney damage. In case of artificial cycle therapy, estradiol valerate should be used together with progestin to protect the endometrium and to regulate menstruation.