The agency was awarded the business without a pitch, and will now be responsible for overseeing a new social media strategy, as well as the implementation of a VO5 "Extreme Style" Facebook page and YouTube channel.
Euro RSCG London already handles the TV advertising for VO5.
Last month, the agency launched a new campaign for the brand called "break the mould", which used dolls to showcase VO5’s new haircare technology that adapts to individual hair types.
Claire Adams, the head of social media for The Cupola Lab, said: "As one of the most innovative haircare brands on the market, we are excited to be working with VO5 to build a community around its product range."
Euro RSCG launched The Cupola Lab in February.