Alli
Alli is an over-the-counter weight loss medication containing orlistat, designed for overweight adults (BMI ≥25) who are trying to lose weight alongside a reduced-calorie, low-fat diet. It works in the digestive system to help block absorption of about one-quarter of dietary fat, which is then eliminated from the body.
Alli is an OTC weight loss aid that blocks fat absorption in the intestines for adults trying to manage their weight.
Key facts at a glance
- RxNorm
- 708361
- Generic
- Alli
- Class
- brand-name
- Brands
- —
- Availability
- rx
- Lactation
- unknown
- Routes
- —
- Forms
- —
- Regions
- US, EU, CN, JP
- Monitoring
- —
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.
Weight management for overweight or obese adults (BMI ≥25). Intended for use in conjunction with a reduced-calorie, low-fat diet and exercise program.
Contains orlistat, which inhibits pancreatic and gastric lipase enzymes in the digestive tract. This prevents the breakdown and absorption of approximately 25-30% of dietary fat, allowing it to be excreted rather than stored.
Common side effects include gastrointestinal symptoms such as oily stools, gas, and frequent bowel movements, particularly when meals contain high fat content. May reduce absorption of fat-soluble vitamins (A, D, E, K); a multivitamin supplement is recommended. Not recommended during pregnancy, breastfeeding, or for individuals with certain conditions like gallbladder disease or chronic malabsorption syndrome. Should be discontinued if weight loss is not achieved after 12 weeks.
Official drug label
WellAlly may earn a referral fee from linked resources at no extra cost to you. Editorial content is never influenced by commercial relationships.
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 31, 2026. · Read our editorial policy