Kérastase Paris Spécifique Masque Hydra-Apaisant, $66.

A hair mask that instantly moisturises and soothes the scalp and softens hair. The renewing gel formula is designed to be used after Spécifique Bain and prior to Spécifique Cure – but we’ll let you in on a secret … it’s excellent even if you use it on its own.