The Hype
NAD+ has become one of the most discussed molecules in longevity. Promoted as a cellular energy restorer, DNA repair accelerator, and aging reverser. Some claims are supported by fascinating preclinical research. Others outrun the evidence.
What NAD+ Does
NAD+ is a coenzyme in every cell. Central to energy production in mitochondria. Critical substrate for sirtuins involved in DNA repair and stress response. Consumed by PARPs for DNA damage repair. By 50, levels may be half of what they were at 20. This decline associates with mitochondrial dysfunction, impaired DNA repair, and cellular aging.
The Evidence
Animal models show improved mitochondrial function, insulin sensitivity, cardiovascular function, cognition, and lifespan with NAD+ boosting. In humans: confirmed that precursors raise NAD+ levels. Improvements in insulin sensitivity and cellular health markers demonstrated. Subjective reports of improved energy and cognition are common. Not yet proven: lifespan extension, aging reversal, or consistent disease-specific outcomes in humans.
Administration Options
Oral precursors: NMN 500-1000 mg daily or NR 300-600 mg daily. Sublingual formulations for improved absorption. Subcutaneous injections for direct bioavailability. IV infusions for highest acute dose but expensive and time-consuming. Injectable provides the most reliable tissue NAD+ increase.
Honest Assessment
NAD+ is one of the more promising longevity interventions but not a proven anti-aging treatment in humans yet. Preclinical data is compelling. Mechanistic rationale is sound. Early human data is encouraging. Claims of reversing aging are premature. For men interested in optimizing cellular function, energy, and recovery, NAD+ supplementation is a reasonable addition to a comprehensive protocol. It should complement, not replace, foundational interventions like training, sleep, nutrition, and hormonal optimization.