Orlistat
Orlistat is a weight management medication that blocks fat absorption in the intestines, prescribed for overweight or obese adults and adolescents aged 12 years and older.
Orlistat is a prescription and over-the-counter weight loss aid that prevents fat absorption from food.
Key facts at a glance
- ATC
- A08AB03
- RxNorm
- 251170
- Generic
- Orlistat
- Class
- atc-a08
- Brands
- Xenical, Alli
- Availability
- otc
- Pregnancy
- B
- Lactation
- caution
- Half-life (h)
- 2
- Onset (min)
- 0
- Duration (h)
- 0
- Routes
- oral
- Forms
- capsule
- Regions
- United States, United Kingdom, Canada, Australia, Germany, France, Italy, Spain, Japan, South Korea, China, India, Brazil
- Monitoring
- liver function tests, stool fat analysis, blood pressure, heart rate, nutritional status
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Orlistat is indicated for weight loss in individuals with a BMI of 30 or greater, or those with a BMI of 27 or greater who have weight-related health conditions such as hypertension, diabetes, or dyslipidemia.
Orlistat inhibits gastrointestinal lipases (enzymes that break down fats), preventing approximately 30% of dietary fat from being absorbed. The undigested fat is excreted in stool rather than stored.
Orlistat should be used alongside a balanced, reduced-calorie diet with no more than 30% of calories from fat. Common side effects include gastrointestinal issues such as oily stools and frequent bowel movements, especially with high-fat meals. Patients should take fat-soluble vitamin supplements at least 2 hours apart from orlistat dosing. Not recommended during pregnancy or for patients with chronic malabsorption syndrome.
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 25, 2026. · Read our editorial policy