Fusio-Dose involves a one step application of a Kerastase ritual by a highly trained Kerastase professional, it is applied using specific massage techniques to stimulate the hair and scalp. The Fusio-Dose ritual is the most personalised service Kérastase offers and is exclusively available in salons. With up to 30 possible pairings, the results are instant and can target two key hair concerns including dryness, damage, frizz, density and dullness.