Another risk with soap brows? It could potentially be rough on your brow hair. "If the soap on your spoolie is too thick, it could pull hairs, leaving patches or gaps," says Bailey. And brow hair can take weeks to grow back.

Is soap bad for your eyebrows?

Mattioli explains that even lower-pH soaps contain surfactants that are designed to be washed away. Therefore, "Leaving them on the skin/eyebrow can absolutely cause dryness and flaking." Plus, she adds, once the soap dries, it could also leave a crusty, flaky residue in your brows.

Are soap brows good?

Zeichner explains it, soap contains a fat known as glycerin that coats the surface of the hairs to keep them in place. Although it won't tint your brow hairs like actual brow styling products can, it works like a charm for shaping them and setting them all day long—and for a fraction of the cost.