Contraceptive patch is a kind of female contraceptive tool, through the form of patch will be estrogen and progesterone through the skin infiltration into the body and produce contraceptive effect. Because the patch needs to be applied to the skin for a long time to release hormones, like other contraceptives, it may cause early pregnancy-like reactions, dizziness, breakthrough vaginal bleeding, menstrual irregularities and other side effects. 1, early pregnancy-like reactions: due to the effect of oestrogen, a small number of people may experience nausea, vomiting, loss of appetite, dizziness, fatigue, and other early pregnancy-like reactions after taking the patch. 2, breakthrough vaginal bleeding: the first few cycles of the patch will usually experience breakthrough bleeding (i.e., vaginal bleeding during non-menstrual periods), which is the first time a person has a pregnancy-like reaction to the patch. Breakthrough vaginal bleeding: the first few cycles of using the contraceptive patch will usually have breakthrough bleeding (i.e., a small amount of irregular vaginal bleeding during non-menstrual periods); 3. Menstrual irregularities: generally manifested as irregular menstrual cycles, shortened menstrual period, less menstrual blood, reduced or disappeared dysmenorrhea, and a small number of people may even have amenorrhea. Shortened menstrual cycles and amenorrhea are due to insufficient progesterone to maintain the growth of the endometrium; 4. Others: breast distension and pain, leukorrhea, increased blood pressure, headache, swelling, weight gain, skin allergies, skin pigmentation, etc. may also occur. In addition, it is not recommended for patients with underlying cardiovascular disease, history of thromboembolism, and embolism in deep veins. If discomfort occurs, it can be treated according to the severity.