Kérastase Blond Absolu Heat Protecting Serum If your process involved harsh bleach, this Kérastase Blond Absolu Heat Protecting Serum ($37) uses hyaluronic acid to fill in hair, so fibres are full and strong once again, and the overall texture is totally resurfaced. Plus, the serum serves as a heat protectant, so hair won't get even more fragile when hot tools are used. Image Source: sephora.com Kérastase Blond Absolu Heat Protecting Serum $37 from sephora.com Buy Now