Our 9-year-old son sleeps incredibly hard (through fire alarms, earth quakes, etc) and prior to switching to Super Undies, was dry overnight maybe once a month. His dr says he'll eventually outgrow this problem but it was so disheartening (& guilt-inducing) buying box after box of pull-ups. We have been using Super Undies for about a month now and while we've had two nights where he leaked through and had to change bedding, he's usually dry or mostly dry now. Unfortunately, he still doesn't wake even when he's wet, but we're hopeful that this product will eventually help train his brain to wake up to use the bathroom instead of peeing while he sleeps. It seems to be doing something since he's having mostly dry nights now! Our son is slim and small-ish for his age and wears a size 3 with an added insert.