Bringing arches back from dangerously thin territory requires a two-step approach.
REBUILD The latest generation of brow-enhancing serums can help with regrowth: Anastasia's Brown Enhancing Serum Advanced ($45) uses a peptide formula that, according to the brow guru herself, strengthens sparse brows and prevents fallout.
FAKE IT Soul Lee, grooming specialist at Manhattan's Spa 1851, suggests filling in with a shadow for extra control of color and blendability--find one that matches your brow color or is one shade lighter, never darker. "Brush the brow with a clean mascara wand to expose the line, then begin filling in with light, short strokes and spread color evenly," says Lee. "Finish with clear mascara."