Maximum Strength Eliminates most fungus on cuticles and skin surrounding nails with regular use. Stops Fungus! 2x the Active Ingredient of other brands! The strongest antifungal treatment available without a prescription. Eliminates most fungus on cuticles and skin surrounding nails. Undecylenic Acid 25% eliminates most cuticle and skin fungus. Inhibits growth jand reproduction of fungal cells. Brush-on Application, no mess and no unpleasant odor. Absorbs quickly. Sally Hansen, the No. 1 name in nail color and care, is committed to providing safe, innovative products that deliver beautiful results.