NMN (Nicotinamide Mononucleotide) is the precursor for NAD+ and is able to promote cellular NAD+ production. It was recently discovered that NMN enters the cells through the Slc12a8 membrane protein which is specifically able to transport NMN but not nicotinamide riboside (according to studies performed on mice). As we age, NAD+ levels begin to decline. NAD+ is required for proper cellular energy utilization and aging accelerates as levels decline. NAD+ is also vital for the bodys ability to repair DNA. Double Wood Supplements NMN supplement capsules are non-gmo, gluten free, and are Manufactured right here in the USA. This product contains a 30 day supply of 1 gram servings.