Up to 90% smoother looking nails, instantly! Fills ridges, salon strength. Salon tested. Results guaranteed (1-800-953-5080). No DBP toluene formaldehyde. America's No. 1 nail brand. What it is: A gel-like base coat that smoothes ridges and imperfections for salon results at home. How it Works: This biotin & spirulina enriched formula, with self-leveling action, fills ridges evenly. Hardens weak nails and adds density to thin nails to help prevent splitting. Even finish grips color. The Results: Smooth, beautiful nails, salon-perfect color application. Based on consumer perception. Biotin, a vitamin found in oysters, & spirulina, a marine extract, are known to help strengthen and nourish nails. sallyhansen.com. Made in USA.