The effective diet drug is orlistat. Obesity is a serious threat to human health. Obesity may lead to hypermetabolic syndrome such as hyperglycemia, hyperlipidemia and hypertension, which will affect the quality of life and shorten the life span. At present, imported weight-loss drug orlistat is widely used in China, and the effect is good. This drug blocks the absorption of fat in the intestine, and about 1/3 of the ingested fat is excreted from the intestine because it cannot be absorbed, thus achieving the purpose of losing weight, improving blood lipid profile and reducing insulin resistance. The recommended dosage is 1.20 mg, taken orally three times a day. The adverse reactions of this medicine can be flatulence, increased stool frequency and greasy stool. Orlistat has achieved remarkable results in the clinical application of weight loss, and its application is safe and convenient.