Stop-it Smoking Anti-Craving Lozenges Formerly NicoRx Gum. Reduces Tobacco Cravings. Calms Nervous Tension. Natra-Bio Stop-it Smoking Anti-Craving Lozenge has been scientifically formulated to reduce the nervousness; anxiety; irritability; and stress related to nicotine withdrawal without any of the hazards of nicotine. Use the lozenges throughout the day for ongoing support. The formula combines the most well-known natural ingredients to minimize your cravings.