Reported timeframes vary from a few days to a few weeks; several products and reviewers note noticeable improvement in about one week.
They can be used in all three ways depending on the product: as a top coat over polish, as a base coat under color, or alone on bare nails. Some formulas are designed specifically as quick-dry top coats, while others are intended for bare-nail strengthening routines.
Common net weights listed include .42 fl oz, .44 fl oz, .45 fl oz, .46 fl oz, and .5 fl oz.
They typically strengthen and fortify nails, reduce peeling, splitting, and breakage, support growth, and add shine. Many formulas also provide quick-drying or protective finishes.
