Biotherm Life Plankton Mask, RM215 (75ml) Biotherm’s Life Plankton Mask is one of the rare beauty products that have made a true difference for my oily skin. What it says An overnight treatment to soothe and repair the skin. Contains Biotherm’s signature Life Plankton, which provides the skin with nutrients, acting as a cellular regenerator. Also suitable for sensitive skin. How it feels The gel texture has a faint aquatic fragrance, which is quite refreshing as the last step of your nighttime facial regimen.