Nicotinamide mononucleotide (NMN) is a naturally occurring molecule found in every living cell of all life forms. At the molecular level, it belongs to a class of molecules called nucleotides, the building blocks of RNA and DNA. Structurally, NMN is composed of three main chemical groups: a phosphate group, a ribose sugar, and a nicotinamide base (see image above). NMN is directly converted to nicotinamide adenine dinucleotide (NAD+), thereby elevating NAD+ levels, which is why NMN is somtimes referred to as an NAD+ booster. https://www.nmn.com/what-is-nmn