Women menstruate when they reach puberty. During different periods of menstruation women’s bodies, emotions and skin change, and in dermatology clinics many skin diseases are related to the menstrual cycle. The female menstrual cycle begins on the first day of menstruation and continues until the next menstrual period. It is divided into four phases: menstrual phase, follicular phase, ovulation phase, and luteal phase. The menstrual phase: generally 2-7 days, this phase is characterized by low body temperature, slow blood flow, reduced skin repair, dull and haggard complexion, and some women are prone to periodic facial acne. During this period, it is important to pay attention to strengthening moisturizing and emolliency, getting enough sleep, not eating cold things, and eating more warm and tonic foods. Such as facial injections and laser treatments with skin breakouts are contraindicated. During this stage, the body’s coagulation function decreases, the body’s resistance decreases, and the chances of bruising and infection from invasive facial treatments increase. Follicular phase: Menstruation is the follicular phase, generally the cycle is maintained for 1-2 weeks, at this stage the secretion of estrogen in the body will increase, the metabolic ability of the skin is improved, the skin color is rosy, and the mood is relaxed, this is the best time for beauty treatment, the treatment effect will be significantly better than other periods, so it is also the golden period for beauty treatment, the chance of discoloration, bruising and infection will be reduced after treatment. Ovulation: Ovulation begins when the egg is mature, which usually occurs on the 14th day of menstruation and lasts for about 48 hours. Some women experience ovulatory bleeding and back pain during the ovulation period, and cosmetic treatments are best avoided during this time. Luteal phase: The period between the day of ovulation and the next menstrual period, usually about two weeks and 14 days after ovulation. During this period, estrogen production decreases and the skin tends to dry out, so skin hydration is especially important during this period. During the late luteal phase, the week before menstruation is the period when the skin is in the worst condition and the worst temperament of the entire 28-day cycle. The skin is dry and dull, resistance to acne easily, the skin is easily sensitive to external stimuli, to do a good job of hydration, sun protection, reasonable rest, you can eat more vitamin C-rich food, such as watermelon, kiwi, beauty treatment can be suspended. Know the four stages will know which period to do beauty or eat food supplements most effective.