Now Foods, Sports, D-Ribose Powder, 1 lb (454 g)Pure Powder Fuels ATP Energy Production Bioenergy Ribose GMP Quality Assured A Dietary Supplement Vegetarian Vegan Ribose is a simple sugar that occurs naturally in all living cells. Ribose is the structural backbone of ATP, the primary form of energy used for cellular processes. Demand for ATP availability is especially critical in the heart and skeletal muscle and Ribose supplementation can help to maintain optimal energy levels in these tissues.