The application of marine resources for the formulation of cosmetics has been known for centuries. Marine organisms produce unique compounds, which are not found in terrestrial sources, to provide protection against hard environmental conditions. They have been used both to confer:
Physicochemical functional properties to the cosmetic product, such as texture, emulsifying properties or color, Bioactive properties, including remineralizing, emollient, hydrating, antioxidant, sunscreening among others.
In this chapter, the major functional and biological activities of components isolated from marines sources, including micro and macroorganisms and with special emphasis on algae, are reviewed in relation to their application to cosmetics. Both the traditionally used compounds and fractions and those isolated and characterized in recent years are presented.