PROCISTIN® D-MANNOSE D-mannose is a natural structural component of the bladder mucosa. Bacteria have the ability to stick there and cause inflammation. When D-mannose is taken as a supplement, it is not broken down and reaches the urinary system intact, where it is eliminated by diuresis. The bacteria recognize D-mannose and now attach to this free form of the monosaccharide and then remove it through the urine. ouromanoz® RAPID has natural D-mannose from dry extract of birch (Betula pendula), free of allergens and other sugars.