The effects of missed doses of Mafron are: it affects the effectiveness of contraception and may cause unplanned pregnancy; it can cause breakthrough bleeding and affect the menstrual cycle, etc. The main mechanism of action is to increase the consistency of the cervical mucus, which increases the resistance to sperm penetration and prevents sperm-egg union, thus playing a contraceptive role. Mafron is taken on the first day of menstruation for 21 days, and the next cycle is usually started on the seventh day after stopping the pill. However, if you miss a dose for more than 24 hours, you can take it in time. If a woman is taking Mafron for contraception or to adjust her menstrual cycle, she can set an alarm clock at a fixed time to remind herself to take the pill in order to avoid missing a dose.