NAD +

NAD+ is described as a central cellular coenzyme used in redox reactions and energy metabolism (glycolysis, TCA cycle, oxidative phosphorylation) and as a required substrate for maintenance pathways including DNA repair and mitochondrial biogenesis. The protocol notes that NAD+ levels decline with age and metabolic stress, which is framed as a contributor to reduced mitochondrial function and weaker cellular resilience. The page summarizes that most clinical research has historically used high-dose intravenous infusions (hundreds to ~1,000 mg) for acute metabolic support and addiction-related protocols, with pilot infusion studies described as well tolerated without acute toxicity. Because IV delivery requires clinical infrastructure, the protocol presents subcutaneous (or intramuscular) dosing at lower amounts as a practical maintenance approach, using gradual titration to improve tolerability. Overall, the mechanism narrative is that replenishing NAD+ pools may support energy production and repair pathways, but dosing and response are highly dependent on route and escalation speed.