Nicotinamide mononucleotide (NMN), which has recently been spotlighted as an anti-aging agent, is a precursor of the coenzyme nicotinamide adenine dinucleotide that plays an important role in intracellular redox reactions. NMN capsules for oral administration currently on the market have a problem in that they are almost fully metabolized in the stomach and liver and excreted as nicotinamide. Therefore, there is a need to develop a patient-friendly delivery method that can improve the bioavailability of NMN. For this purpose, various polyvinyl alcohol (PVA)-based microneedle patches were fabricated to develop a transdermal delivery system for NMN. First, the molecular weight effect of PVA on the shape and microstructure of microneedles was studied. After selecting the optimal molecular weight PVA, the swelling of the microneedles and the ex vivo release of NMN were studied. The effect of carboxymethyl cellulose (CMC) and dimethyl sulfoxide on NMN release was also investigated. The highest NMN release of 91.94% in 18 h was obtained using a 9.5 kDa molecular weight PVA microneedle containing NMN and CMC.