To help yourself lose this nasty habit, Mavala Laboratories have developed a completely harmless, transparent, bitter product that goes on like nail polish: Mavala Stop. It quickly removes the urge to chew your nails. It's also recommended for children, because its non-toxic but unpleasant flavor takes away children's desire to suck their thumb. It's easy to use, and by simply applying it every two days, you'll no longer have to hide your hands.