Nicotinamide adenine dinucleotide metabolism and arterial stiffness after long-term nicotinamide mononucleotide supplementation: a randomized, double-blind, placebo-controlled trial | Scientific Reports

A 12-week randomized clinical trial investigated the effects of 250 mg/day oral nicotinamide mononucleotide (NMN) supplementation on NAD+ metabolism and arterial stiffness in 36 healthy middle-aged adults. Results showed that NMN intake significantly elevated serum nicotinamide levels, indicating increased NAD+ metabolism, and was well tolerated without adverse events. While pulse wave velocity measurements suggested a trend toward reduced arterial stiffness in the NMN group, the difference compared to the placebo group was not statistically significant.