Now's D-Mannose helps reduce the risk of recurrent urinary tract infections in women. D-Mannose is a sugar found naturally in certain plants, such as cranberries. Although small quantities of D-Mannose are metabolized by the human body, a large proportion is rapidly excreted in the urine. In the bladder, D-Mannose can adhere to unwanted foreign substances, preventing them from sticking to the bladder mucosa.