Davines released its first collection of products in 1996 after formulating some of the best hair care for other brands. It uses high quality, ethically sourced ingredients, keeping the environment and sustainability top of mind throughout every part of the brand. A Single Shampoo (£20.50) is 100-percent carbon neutral and contains a surfactant made from olive oil sourced partially from the Quercetano Olive Slow Food Presidium of Tuscany, which was set up by the brand in 2017 to support biodiversity. Basically, it's the most sustainable shampoo in the world.