The duration of side effects of Exemestane is related to the individual’s physical condition as well as the dose of the drug, and it is usually able to be relieved in 2~3 days after stopping the drug. Exemestane is an antitumor drug, mainly used as an adjuvant treatment for breast cancer. Side effects of drugs refer to pharmacological reactions other than the therapeutic purpose under normal dosage, and most drugs may have side effects. Exemestane prevents estrogen biosynthesis by inhibiting aromatase, irreversibly binding to and inactivating aromatase. The most commonly reported adverse effects of this drug are hot flashes, arthralgia, and fatigue. Most of the adverse effects are due to normal pharmacologic responses (e.g., hot flashes) that occur when estrogen production is blocked. Usually, these side effects resolve 2 to 3 days after discontinuation of the drug. When using medication, patients need to follow the doctor’s instructions to choose the correct usage and dosage, which can reduce some of the side effects to a certain extent. When side effects occur, the patient should go to the hospital in time and be treated under the doctor’s supervision.