Taking orlistat without menstruation, mainly may be due to two reasons, one is orlistat cause menstrual irregularities, the other is taking orlistat during the female pregnancy. First, the impact of drugs orlistat is a kind of weight loss drugs, mainly through the inhibition of fat absorption in the intestinal tract, to achieve the effect of slimming, there will be certain side effects, mainly for gastrointestinal dysfunction, some patients will also appear in the delayed menstruation or even do not come to the symptoms. In addition, orlistat may not only cause menstruation to stop, but also affect the absorption of fat-soluble vitamins, such as vitamin B12, vitamin D, causing vitamin deficiency in the body, low immunity, but also may appear itchy skin, angioneurotic edema, urticaria, and other allergic reactions, but the symptoms are generally mild, and the symptoms can be relieved after stopping the drug in time. Second, physiological and pathological factors 1, pregnancy: during the use of orlistat, if a woman is pregnant, symptoms of menopause can also occur. Patients should promptly go to the hospital to check the blood, urine HCG and abdominal ultrasound, to determine whether the pregnancy and whether the embryo is developing normally, pay attention to regular checkups during pregnancy to determine fetal growth and development; 2, endocrine disorders: such as hyperadrenocorticism, diabetes mellitus, etc., is a common reason for not having a menstrual period, not much correlation with the use of orlistat. Diabetic patients should actively monitor blood glucose, treatment of primary disease, hyperadrenocorticism need to regulate the endocrine under the guidance of the doctor; 3, other: during the period of taking orlistat, when the female pituitary gland lesions, such as pituitary gland dysfunction, pituitary tumors, and ovarian lesions, ovarian cysts, ovarian dysplasia, etc., can lead to menstruation, should be carried out in a timely manner. All of them can lead to lack of menstruation and should be treated with symptomatic drugs or surgery in time. Therefore, it is not advisable for women to use drugs to lose weight, as drugs can produce side effects and damage the health of the body. They should adopt a healthy way to lose weight, adjust their diet structure, eat less high sugar, high oil, high fat food, such as cakes, fried chicken, etc., and exercise moderately after meals to reduce the time of sitting and lying down.