Here is how alli works - You may take alli 1 hour before your meals, with your meals or up to 1 hour after your meals. Usually alli stays in your body for about 2 hours, therefore, it may works up 2 hours after your meal but not 2 hours before your meal. Hope this helps.
Let me know if you have any other questions,
Sylvia
Sylvia Melendez-Klinger, MS, RD, LDN, CPT - registered dietitian