Compare Supplements

Prescription Xenical: 120 mg three times daily (360 mg/day), taken with or up to 1 hour after each main fat-containing meal. Over-the-counter Alli: 60 mg three times daily (180 mg/day). Skip the dose if a meal is missed or contains no fat. Used alongside a reduced-calorie diet in which fat supplies roughly 30% of energy — a higher-fat meal makes the gastrointestinal side effects markedly worse, not the weight loss better.

With meals · with food

Xenical 120 mg capsule three times daily with meals (prescription)

Once-weekly subcutaneous injection, started at 2.5 mg and escalated by 2.5 mg every 4 weeks to a maintenance dose of 5, 10, or 15 mg (per the prescribing physician and approved indication)

Any time

Once-weekly subcutaneous injection (Mounjaro / Zepbound)

• Chronic malabsorption syndrome
• Cholestasis
• Pregnancy — intentional weight loss is not a therapeutic goal in pregnancy, and orlistat measurably lowers vitamin D and impairs vitamin E and K absorption (McDuffie 2002)

• Warfarin
• Levothyroxine (thyroxine)
• Ciclosporin (cyclosporine)

• Personal or family history of medullary thyroid carcinoma (MTC)
• Multiple endocrine neoplasia syndrome type 2 (MEN2)
• History of pancreatitis (use with caution / avoid)

• Oral contraceptives
• Insulin and sulfonylureas
• Oral medications generally