Weight management in adults with obesity, alongside diet and physical activity, under UK prescribing criteria. A lower‑dose version (Alli 60 mg) is available pharmacy‑only.

Take one 120 mg capsule with water just before, during, or up to 1 hour after each main meal containing fat (up to three times daily). Skip the dose if a meal is missed or contains no fat.

120 mg up to three times daily with fat‑containing meals. Take a multivitamin containing fat‑soluble vitamins (A, D, E, K) at bedtime, at least 2 hours after Xenical.

Oily or fatty stools, urgent or increased bowel movements, flatulence with discharge, abdominal pain—especially if dietary fat is high. Less common: faecal incontinence, headache, and rarely liver injury.

Alcohol has no direct interaction with orlistat but is high in calories and may worsen GI symptoms when combined with high‑fat foods. Limiting alcohol supports weight loss.

Weight loss is generally modest versus GLP‑1‑based therapies but it is non‑systemic (acts in the gut) and suitable for some patients who cannot use injectable therapies. GI effects are diet‑dependent.

GI side effects, reduced absorption of fat‑soluble vitamins, rare liver or kidney problems. Contraindicated in chronic malabsorption syndrome or cholestasis. Not recommended in pregnancy or breastfeeding.

Avoid ciclosporin (separate by several hours and monitor if co‑prescribed), monitor warfarin/anticoagulants (vitamin K effects), separate levothyroxine by at least 4 hours, and check with your pharmacist about other medicines and supplements.

Patient Information Leaflet, NHS weight management pages, and advice from your prescriber or pharmacist.