I have started using D-RIbose powder. Wanted to share something that I learned.: http://www.bioenergy.com/ Bioenergy holds ALL patents for manufacturing D-Ribose. They sell their product under the brand name Corvalen and also to other companies who market it under their own label. I could not find Corvalen locally but the owner of a local single-store vitaman shop told me that he carries "Jarrow Formulas" and that it is the same product as Corvalen. http://www.jarrow.com/ I tended to believe my vitamin shop owner but also called BioEnergy to inquire. Bioenergy stated what I said at post beginning: "We/ Bioenergy hold ALL patents for manufacturing D-Ribose. We sell our product under the brand name Corvalen and also to other companies who market it under their own label." They stopped short of giving me a list but this is useful knowledge when value-shopping. For me, buying Jarrow's Formulas locally is much cheaper than ordering Corvalen online. cheers!