Why 40% Urea Works Differently
Your skin growths are made of compacted keratin, packed in dense, rigid layers held together by hydrogen bonds. Regular moisturizers sit on the surface. Glycolic acid polishes the outside. Neither one can reach the structure underneath.
At 40% concentration, urea crosses the keratolytic threshold. It penetrates into the compacted keratin and disrupts the hydrogen bonds from within. The dense layers that felt hard, raised, and stuck to your skin begin to loosen and soften.