NMN Nicotinamide MononucleotideExcellent NAD+ Precursor In fact, NMN can go directly into cells and convert to NAD+ in one step. NMN promotes health by activating SIRTUINS, a group of longevity genes that are responsible for repairing DNA damage and regulating or inhibiting other genes. SIRTUINS are dependent on NAD+, which means they cannot function if NAD+ is not in sufficient supply. This is why NMN is so important, as it is the most effective way to increase and support NAD