Acne refers to acne. Acne before a woman’s menstrual period is usually caused by endocrine disorders, and may also be related to diet, sleep and other factors. 1. Endocrine disorders: Women will experience an increase in androgens before menstruation, which can easily lead to acne. Regular use of birth control pills such as Yosmin can reduce the level of androgens in the body before menstruation and improve acne. 2. Improper diet: Poor diet before menstruation may cause acne if you eat a lot of sugary or oily food, so you should adjust your diet to avoid bad eating habits. 3. Sleep factors: Regularly staying up late before menstruation, leading to sleep deprivation, also has the risk of causing acne. You should practice healthy sleeping habits and avoid staying up late so that you can get enough sleep. There may be other reasons for acne before menstruation. It is recommended that you visit a hospital if necessary and take relevant treatment measures under the guidance of your doctor.