Orlistat can lose weight and is currently approved for the treatment of obese and overweight patients in China. The general usage is that adults are advised to take one tablet with meals or within one hour after meals. If you haven't eaten a meal or the food contains no fat, you don't have to take medicine. The common adverse reactions of orlistat include oil spots, gastrointestinal exhaust, urgency in defecation, and some fatty diarrhea, such as greasy stool, increased stool frequency, and some even incontinence. With the increase of dietary fat, the incidence of these adverse reactions will increase correspondingly, but most patients can be improved after taking the medicine for a period of time. Generally, there are many acute gastrointestinal reactions, such as abdominal pain, abdominal discomfort, flatulence, watery stool and rectal discomfort. Some rare adverse reactions were observed, such as upper and lower respiratory tract infections, influenza, headache and urogenital tract infections. Occasionally, there are reports of allergic reactions to orlistat, but such reports are rare. Common clinical manifestations such as rash, urticaria, angioneurotic edema, bronchospasm and other allergic reactions are rare. In addition, patients with hyperlipidemia, hypertension, diabetes and fatty liver above moderate level need to take drugs under the guidance of professional doctors.