The agency has been hired following a competitive pitch and replaces incumbent agency Henry's House which had held the account for one of the brands.
Bio-Synergy makes nutrition and sports drinks and supplements and is headed by CEO Daniel Herman.
Shareholders in the company include sports hero and chairman of the London Organising Committee for the 2012 Olympic Games Lord Coe.
Most recently Bio-Synergy worked with Hollyoaks actress Hannah Tointon to promote one of its products, Skinny Water.
Bio-Synergy's products are distributed in numerous high street retailers including Tesco, Sainsbury's, Asda, Superdrug, Argos, Littlewoods and Holland & Barrett, as well as catalogues and online.