Adir and Vanessa add that you don't have to get rid of the keratin aspect completely, especially if said treatments make the texture of your hair more manageable on a daily basis, but it pays to use products which will condition and maintain elasticity in the hair to tone down the effect of the hair-hardening protein. "Make sure your aftercare is not protein-based," advises Vanessa. "Most 'restructuring' or 'rebuilding' hair products include protein to strengthen, so must be avoided. Instead, use nourishing and moisturising products." Her top recommendation? Hair oil post-hair wash to keep lengths glossy . A pro go-to, Kérastase's Elixir Ultime L'Original Hair Oil, £43, nourishes, softens and maintains flexibility. Also try Hask Argan Oil From Morocco Repairing Shine Hair Oil, £3 , and Dove Advanced Hair Series Shine Revived Oil Treatment, £7.75