The most widely known non-prescription tablet is Zotrim but I've not heard much about its effectiveness. In theory it slows down the rate at which food empties from your stomach, making you feel fuller for. Would be worth doing your research before shelling out hard-earned cash though. Good, proven, options include having a cup of low-fat homemade soup when you are peckish, having a cup of water with Psyllium husks mixed in (tastes like wallpaper paste and shouldn't be drunk more than once a day but is cheap from health food shops and does fill you up - as well as being a healthy laxative!!!) I also find that protein fills me up better than carbs, so a multigrain Ryvita topped with a couple of spoons of cottage cheese or houmous fills me up as a snack better than hi-carb fruit.