While ACV cannot lower the natural porosity of your hair or repair holes in the cuticle layer caused by heat or chemical damage, it flattens the hair cuticle to mitigate the effects of high porosity hair. This makes your hair smoother and easier to detangle, shinier, less frizzy, less prone to breakage, and more moisturized. By lowering the pH of your scalp, ACV flattens and closes the hair cuticle.