The agency will handle creative, digital, press and experiential activity for the division, which comprises the La Roche-Posay and Vichy skincare brands and the fragrance brand Roger & Gallet.
The division has previously worked with a number of different agencies on a project basis.
TRBR won the account following a four-way pitch managed in-house by L'Oréal UK. Interestingly, L’Oréal paid a £5,000 pitching fee to the unsuccessful agencies that were shortlisted to the final stage.
The change does not affect L'Oréal’s global relationships – for example, TBWA holds the global creative account for Vichy.
Cris Burson-Thomas, the integrated marketing communications director at L'Oréal UK Active Cosmetics Division, said: "We are confident TRBR is the right partner to help us become even more integrated in our communications and generate exciting creative ideas that will inspire consumers to choose our three great brands."
The Red Brick Road will work alongside L'Oréal UK’s other retained agencies Maxus (media), Dowal Walker (PR) and iCrossing (search).
David Miller, the chief executive at TRBR, said: "It's fantastic to have the scope to deliver our integrated thinking and creativity for such great, trusted brands. We can't wait to get started with Cris and his ambitious team."
Yannick Raynaud, the managing director of the Active Cosmetics Division in the UK and Ireland, which is L’Oréal UK’s fastest growing division, said it wanted a single integrated agency because it needs a "flexible and creative agency partner who understands content/comms and the consumer journey to generate even more integrated ideas and help us achieve our ambitious growth targets".