Stop & Grow, Willpower in a bottle! End nail biting today. From the very first application- double acting Stop’n Grow will help you stop nail biting. The unique formula contains two powerful ingredients to make it doubly effective. Stop’n Grow produces a very bitter taste to stop you biting your nails immediately. It’s strong bitter taste acts as a constant warning when fingers begin to stray to the mouth. Within three weeks your nails will be longer and more attractive. Double acting Stop’n Grow is willpower in a bottle.