NAD+ Decline: Why Your 40s Feel Different

By age 50, your NAD+ levels are roughly half what they were at 20. NAD+ is the cofactor that sirtuins (your longevity genes) need to function. NMN and NR are the two precursors with the most human data; a 2022 Washington University trial showed NMN raised NAD+ in skeletal muscle and improved insulin sensitivity in postmenopausal women.