I smoked almost daily and they piss tested me twice a month but i was clean everytime. It's because i went to GNC and got these pills that are called "Niacin". I think they're diet pills but i would take 2 pills 2 days before my drug test and the pills clean out your system. I had no side effects when i took them and they're like 6$ for a bottle with about 15 pills. This is a a good way to clean out your system without having to pay 30$ for a bottle that might not work at a head shop.