I have used fresh garlic from the store, never bought garlic guard. It's probably just as effective either way. What I do is crush the garlic in a little cup of water then soak the pellets in there. Right before I put the pellets in I put a little bit of the crushed garlic right in the tank- you can see the fish perk up and get hungry. Seems to work pretty well. I use this mostly to get fish to eat medicated food that they are wary of.