The present invention relates to extracts of Tetraselmis sp., preferably Tetraselmis suecica, its cosmetic, dermatological and/or therapeutic uses and compositions and cosmetic, dermatological or therapeutic products comprising such an extract of Tetraselmis sp., preferably Tetraselmis suecicaThe extract can be used to inhibit hair growth, lighten hair and/or skin or modulate the level of CE protein components such as filaggrin and/or involucrin.