Xenical and Alli dosage — 120 mg vs 60 mg

The strength. Xenical is a prescription 120 mg capsule taken three times a day with meals that contain fat. Alli is the over-the-counter version at 60 mg, taken with each meal containing fat and capped at 3 capsules a day by its Drug Facts label. Both contain orlistat and both are labelled for use alongside a reduced-calorie, low-fat diet.

The Xenical label says to take the capsule with each main meal containing fat — during the meal, or up to one hour after it. The daily intake of fat, carbohydrate and protein should be spread over three main meals.

The label says that if a meal is occasionally missed, or contains no fat, the dose of orlistat can be omitted. Orlistat works on fat in the meal itself, so there is nothing for it to act on.

No. The Xenical label says doses above 120 mg three times a day have not been shown to provide additional benefit, and the Alli Drug Facts label says not to take more than 3 capsules daily.

Because orlistat reduces the absorption of some fat-soluble vitamins and beta-carotene. The Xenical label says to take a multivitamin containing vitamins A, D, E, K and beta-carotene once a day, at least 2 hours before or after orlistat, such as at bedtime. The Alli label says to take a multivitamin once a day at bedtime.

The label says that, based on fecal fat measurements, the effect of Xenical is seen as soon as 24 to 48 hours after dosing, and that fecal fat content usually returns to pre-treatment levels within 48 to 72 hours after stopping. At the 120 mg three-times-daily dose, the label says orlistat inhibits dietary fat absorption by approximately 30%.