Well, to be honest i took it on an empty stomach because i read it reacted with food in your stomach and oxidise (i think is the right word) your food. i found the link i provided after a quick google search and thought maybe there was more to it than i had understood.
But i definitely remember more digestion and stomach problems when i used to only wait 30mins after drinking h2o2 before eating, but then again i was on a lot more drops, upto around 15-20 at a time in 16oz water