Olaplex No.7 Bonding Oil Often used as the last step in the Olaplex process, the Olaplex No.7 Bonding Oil ($28) can be applied before or after blowing out your hair to prevent frizz, heat damage, and split ends. If your hair is colour-treated, you can also use this product to protect the colour's vibrancy. Image Source: olaplex.com Olaplex No.7 Bonding Oil $28 from olaplex.com Buy Now