DUDU OSUN Tropical Natural Black Soap ( 150g) Made with a rich infusion of essential all-natural ingredients, our black soap is renowned globally for its superior skincare properties. Dudu-Osun black soap is clinically proven to smoothen the skin and reduce skin redness. In a clinical study under dermatological control of thirty (30) subjects, Dudu-Osun black soap proved to significantly improve skin moisturization after 28-days.