Under normal circumstances, patients taking anti-allergy medication will not affect their menstruation. Because anti-allergy medications are not hormonal and do not cause hormonal imbalance in the patient’s body, they have very little effect on menstruation and can be used with confidence. If a patient experiences irregular menstruation while taking anti-allergy medication, it may be due to the disease itself. First, because a woman’s body is weaker when she is allergic, it may lead to delayed menstruation or heavy menstruation. Secondly, it may also be due to emotional irritability, mental stress, poor sleep and other factors that may lead to menstrual disorders in women with allergies.