Given that NR and NMN increase NAD+ levels, they are often called NAD boosters. NR (nicotinamide riboside) and NMN (nicotinamide mononucleotide) supplements are both often touted as two of the most promising ingredients to slow down aging. NR and NMN are precursors to NAD+ (nicotinamide adenine dinucleotide). This means NR and NMN are converted into NAD+. NAD+ is a very important molecule, having a myriad of effects in our body.