Nailtiques Formula No. 2

When it comes to fortifying brittle nails, this blend of keratin, protein, and calcium does the trick. "I use it on models with nails weakened by acrylic tips," says N.Y.C. manicurist Tatyana Molot. If you apply two coats, it'll help smooth bumps and fill in ridges like a base coat, adds Candice Manacchio, who cares for cuticles in Connecticut.