The invention relates to a cosmetic or dermatological agent consisting of galactomannans obtained from Caesalpinia spinosa and having a molar mass of between 1 and 150kDa and cross-linked sulphated galactans obtained from Kappaphycus alvarezii and having a molar mass of between 1 and 150kDa. The invention also relates to the uses of said agent, in particular for its tightening and film-forming effect.L'objet de l'invention est un agent cosmétique ou dermocosmétique, constitué de galactomannanes obtenus à partir de Caesalpinia spinosa de masses molaires comprises entre 1 et 150kDa et de galactanes sulfatés réticulés de Kappaphycus alvarezii de masses molaires comprises entre 1 et 150kDa. L'invention vise aussi les utilisations de cet agent en particulier pour son effet tenseur et filmogène.
