NAD+ Restoration

The NAD+ Restoration stack combines senolytic therapy with direct NAD+ replenishment to address two interconnected hallmarks of aging: cellular senescence and metabolic cofactor depletion. FOXO4-DRI is a D-retro-inverso peptide that disrupts the interaction between FOXO4 and p53 in senescent cells. Normally, FOXO4 sequesters p53 in the nucleus of senescent cells, preventing them from undergoing apoptosis. By competitively binding FOXO4, the DRI peptide frees p53 to trigger apoptotic pathways specifically in senescent cells — those dysfunctional cells that accumulate with age and secrete inflammatory factors (SASP) that damage surrounding healthy tissue. In the landmark 2017 study by Baar et al. published in Cell, FOXO4-DRI administration to aged mice restored fitness, fur density, and renal function by selectively clearing senescent cells. This represents a true senolytic mechanism — killing aged cells rather than trying to rejuvenate them. The D-retro-inverso modification makes the peptide resistant to proteolytic degradation, giving it extended biological activity. NAD+ intravenous infusion provides direct restoration of this critical coenzyme, bypassing the multi-step oral conversion pathway (NMN → NAD+ requires enzymatic steps that may be rate-limited in aging tissues). NAD+ is required for sirtuin activation (SIRT1-7), PARP-mediated DNA repair, mitochondrial electron transport, and circadian clock function. The combination logic is that clearing senescent cells (FOXO4-DRI) removes the source of inflammatory signaling that depletes NAD+ in neighboring cells, while NAD+ infusion restores the metabolic capacity of remaining healthy cells. This represents a cutting-edge research protocol — FOXO4-DRI has no human clinical trials, and the stack should be understood as experimental and hypothesis-driven.