A method and a substance for strengthening fingernails and toe nails of a human being. The method comprises the steps of providing a substance comprising a natural oil composition, a bioactive glass composition and a solvent applying the substance topically to an outer surface of the fingernail or toe nail and allowing the substance to dry on the outer surface. The natural oil composition comprises a self-polymerizing oil with an Iodine Value greater than 140. The solvent may be operable to remove nitrocellulose-based fingernail polish. The relative amounts of natural oil composition, bioactive glass composition and solvent are such that the substance is operable to harden and strengthen the fingernail or toe nail.
