28 Nov 2023 --- Korean scientists warn washing hair with surfactants can cause structural damage while decreasing its internal density. They believe cuticle-sealing formulations may effectively inhibit this phenomenon. “Generally, thicker hairs contain more than one loosely packed porous region, called the medulla, located near the center of the hair. These multiple porous regions appear spherical and hollow inside a series of vacuoles along the fiber axis” explain the researchers, writing in Cosmetics.
