The main function of the contraceptive patch is to prevent pregnancy. The patch is absorbed into the body through skin penetration, inhibiting the release of eggs and making the cervical mucus sticky, which is not conducive to the passage of sperm, thus providing a contraceptive effect. Contraceptive patch generally need to be based on the menstrual cycle, from the first day of menstruation to paste, change once a week, in the fourth week of menstruation will not need to paste. The patch is effective in preventing menstrual cramps and relieving menstrual cramps. The effect is not good for women who are too obese or whose skin is slow to absorb, and women who have cardiovascular diseases or who are planning to have children in the near future should not use it. Redness or itchiness in the area where the contraceptive patch is applied is considered to be skin allergy and needs to be suspended from use.