Logically, you can take 2 Alli instead of one Xenical because both contain same ingredient "Orlistat". Xenical is available in 120 mg and Alli in 60 mg. Xenical is prescription drug while Alli is OTC. But from safety point to view, you should not take because recommended dose of OTC Alli is 60 mg three times a day. It will be better to discuss with doctor who has prescribed Xenical to you.
