Hair building fibers, also known as hair thickeners, are microscopic keratin strands that cling to existing hair, creating the illusion of added volume and thickness.
Widely used to combat thinning hair and hair loss, hair building fibers are a non-surgical, non-invasive solution that offers immediate, noticeable results. Their popularity surged with the invention of colored fibers, which seamlessly blend with the user's natural hair color for a natural appearance.