NAD+ is a coenzyme central to redox reactions, energy metabolism (glycolysis, TCA cycle, oxidative phosphorylation), and cellular maintenance pathways including DNA repair and mitochondrial biogenesis[1]. Cellular NAD+ levels decline with age and metabolic stress, which may contribute to reduced mitochondrial function and impaired cellular resilience[8]. Clinical research on NAD+ therapy has primarily used intravenous infusions at high doses (500–1,000 mg) for applications such as addiction treatment and acute metabolic support[2][9]. A pilot metabolic study demonstrated that a 750 mg NAD+ IV infusion over 6 hours was well‑tolerated in humans, with rapid metabolic clearance and no acute toxicity[10]. However, IV administration requires clinical supervision and specialized equipment. Subcutaneous (SC) or intramuscular (IM) injections at lower doses (tens to low hundreds of milligrams) are emerging as practical alternatives for maintenance therapy and wellness applications[3][11]. Compounded NAD+ can be administered SC in small volumes, and SC self‑injection is convenient for ongoing use[12]. Conservative protocols start around 50–100 mg per injection a few times per week; the present protocol uses daily SC administration with gradual titration to optimize individual tolerance and response.
