Orlistat is a drug designed to treat obesity. It is marketed as a prescription drug under the trade name Xenical by Roche in most countries, and is sold over-the-counter as Alli. This medicine must be used together with a reduced-calorie diet. Orlistat is for use only in adults. Xenical is the prescription-strength form of orlistat. The alli brand is available without a prescription.

Orlistat interactions. Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Some products that may interact with this drug include: “blood thinners” (such as warfarin), HIV medications (such as atazanavir, efavirenz, emtricitabine, lopinavir, ritonavir, tenofovir).