It is recommended to stop taking Orlistat for 3 to 5 days before donating blood. Orlistat is a gastrointestinal lipase inhibitor that reduces triglyceride absorption and thus calorie intake, and can be used to reduce the risk of obesity-related diseases such as hypertension, type 2 diabetes mellitus, and hyperlipidemia. Adverse reactions such as fatty stools, increased gastrointestinal gas, abdominal pain, respiratory infections, and headache may occur after taking orlistat. It takes 3-5 days for orlistat to be completely eliminated through feces and urine, so people who need to donate blood are advised to stop taking the drug for 3-5 days before donating blood. It is important to note that you should maintain a light diet and avoid a high-fat diet before donating blood. Patients who are taking Orlistat are advised to donate blood under the guidance of a doctor.