Alli 120 Product Information and Features Prices. Alli 120 General Feedback is Good. Well worth the buy. Alli may be the reduced-strength version of orlistat (Xenical), a prescription drug to deal with weight problems. It’s approved for over-the-counter purchase to overweight grown ups 18 years and older. Alli is intended to be used along with a minimal-calorie, low-body fat diet and physical exercise. - Read more