David prefers NMN over NR (Nicotinamide Riboside) for several reasons based on his research and understanding of the two compounds: NMN is more direct in the NAD+ biosynthesis pathway: Both NMN and NR are precursors to NAD+, a crucial coenzyme found in every cell of our bodies and involved in hundreds of metabolic processes. However, NR must be converted into NMN before it can be utilized to create NAD+. NMN, therefore, might be a more direct and efficient way to replenish cellular NAD+ levels. Evidence of superior health benefits: Some studies suggest that NMN may have more extensive effects on health and aging compared to NR. These benefits include partially reversing vascular aging, improving endurance in old mice, improving aging metabolism, and even restoring fertility in old animals. However, more research is needed to definitively determine the comparative benefits of NMN and NR in humans. Personal experience and belief: David Sinclair takes NMN himself, believing in its efficacy. He is also a co-founder of Metro Biotech, a company developing NMN-based molecules to treat aging and aging-related diseases. This shows a significant investment in NMN, both personally and professionally.