The difference between NMN or NR comes down to your perspective of the science behind each compound.The target for both compounds is to increase NAD+ levels in the body. NAD+ is critical for life and declines dramatically as we age. Both NMN and NR are precursors to the creation of NAD+ in the body. This article is a good summary of the science and research behind both compounds. https://blog.insidetracker.com/nr-nmn-longevity-supplements-work-humans.We have a number of customers currently taking both, reporting benefits from each. There is evidence that cycling supplements (i.e. not taking every day) has a positive effect on the body's reaction to the active ingredients. It could be that alternating between NMN and NR each day would enable the best of both worlds, but there is no studies on this to date.