NAD+ (Injectable)

NAD+ (Nicotinamide Adenine Dinucleotide, oxidized form) is not a peptide — it is a coenzyme present in every cell of the body and central to redox metabolism, ATP production, DNA repair, and sirtuin signaling. It is included on this site because uk-peptides.com and other vendors sell injectable and intranasal NAD+ alongside their peptide catalog and it has become a popular longevity intervention. The premise of NAD+ supplementation is that cellular NAD+ levels decline substantially with age (by approximately 50% between young adulthood and middle age in some studies) and that this decline contributes to many of the cellular hallmarks of aging — including reduced sirtuin activity, impaired DNA repair, mitochondrial dysfunction, and chronic inflammation.

NAD+ can be raised pharmacologically by direct administration of NAD+ itself, or by supplementation with NAD+ precursors (nicotinamide riboside / NR, nicotinamide mononucleotide / NMN). Oral bioavailability of direct NAD+ is poor, which is why injectable and intranasal formulations are sold. IV NAD+ infusion has been used in addiction recovery clinics for decades (the "Brain Restoration Plus" protocol) and has emerged into mainstream wellness use for anti-aging, energy, and cognitive applications.

Evidence is mixed. Small clinical studies of NAD+ precursors (NR, NMN) have shown that they reliably raise blood NAD+ levels and produce some measurable changes in metabolic markers. However, large clinical evidence of meaningful longevity or healthspan effects in humans is limited, and several proposed mechanisms remain debated. Subjective user reports of energy and mental clarity from injectable NAD+ are common but inherently anecdotal. The peptide is generally safe but is best understood as a research-grade intervention rather than a proven anti-aging therapy.

NAD+ was discovered as a coenzyme by Arthur Harden and William John Young in 1906 (work for which Harden shared the 1929 Nobel Prize). Its role in sirtuin-mediated longevity signaling was established by David Sinclair, Leonard Guarente, and colleagues from the late 1990s onward. The clinical use of IV NAD+ in addiction medicine dates to the 1960s. The modern wave of NAD+ longevity supplementation began in the 2010s following Sinclair-group work on NAD+ precursors and aging in mice, and has since expanded into a substantial wellness industry around NR, NMN, and direct NAD+ administration.