Plankton Extract Good Humectant Hydration Plankton Extract description A marine species known as Thalasso plankton and derived from various algae, seaweed, or marine skeletons. There is no research showing plankton extract has any benefit for skin but, like most forms of algae, it can have moisture-binding properties. Although that’s good, keep in mind plankton isn’t a miracle (not even a minor one) or a must-have ingredient for skin. Related ingredients: Algae