Over 50 years ago, when Biotherm biologists first took an interest in thermal plankton, they discovered its perfect affinity with the skin and its remarkable effectiveness. Because of these exceptional properties they made the decision to create the first skin care line with thermal plankton. 20 years of research were necessary for Biotherm Biologists to isolate this substance and subsequently reproduce it by bio-fermentation to obtain an even more active and concentrated form: Pure Thermal Plankton. Pure Thermal Plankton is 100% Natural as its origins are at the very heart of mineral springs. It is also Pure as Biotherm Biologists succeeded in extracting an extremely pure concentrate through bio-fermentation. It is finally Active because it helps protect skin's natural defences.