Apple Cider Vinegar Thin2Thick™ Shampoo and Conditioner helps promote hair thickness, restoring its vibrant shine and luster. It contains biotin, an important hair vitamin that fortifies every strand for thicker-looking hair. Keratin helps strengthen hair by reducing frizz and tangles. Apple Cider Vinegar cleanses and clarifies the scalp to help reduce buildup that causes itching and flakes. 8 oz.