β-nicotinamide mononucleotide has several beneficial pharmacological activities. Mostly mediated by its involvement in NAD+ biosynthesis, the pharmacological activities of NMN include its role in cellular biochemical functions, cardioprotection, diabetes, Alzheimer's disease, and complications associated with obesity.
The intracellular NAD+ levels are significantly decreased by knockdown or knockout of Nampt (Nampt KD or Nampt KO) or treatment with Nampt inhibitor FK866, whereas NAD+ levels are dramatically increased by supplement of NAD+ precursors NAM or NMN (0.5–1 mM). NAD+ precursor NMN treatment inhibited CD8+ T cells activation and function.

β-Nicotinamide mononucleotide (500 mg/kg; i.p.; 3 times per week for 7-10 week) prevents mtDNA damage and Dox-induced cardiac dysfunction.
Nampt KO markedly inhibits tumor progression, whereas Nampt metabolite β-Nicotinamide mononucleotide (300 mg/kg body weight; i.p.; once every two days for 2 weeks) significantly promotes tumor growth in C57BL/6 mice (bearing wildtype Hepa1-6 cells). The reduction and increase in NAD+ level of respective Nampt KO and β-Nicotinamide mononucleotide-treated tumors are confirmed.
β-nicotinamide mononucleotide ameliorates glucose intolerance by restoring NAD(+) levels in HFD-induced T2D mice. β-nicotinamide mononucleotide also enhances hepatic insulin sensitivity and restores gene expression related to oxidative stress, inflammatory response, and circadian rhythm, partly through SIRT1 activation.