A systems approach to restoring cellular energy, DNA repair and circadian regulation
Source: Dr. Nichola Conlon × Ben Greenfield Podcast · Supplemented with current scientific literature
NAD⁺ is naturally present in every cell of the body. It drives over 300 reactions — the key ones being energy production in mitochondria (Krebs cycle) and DNA repair / sirtuin activation. Levels decline by roughly half every 20 years from birth. At age 40 you have ~¼ of a newborn's levels.
NAD⁺ accepts and donates electrons in the electron transport chain → ATP production. In this process NAD is not consumed, it merely switches states.
Sirtuins, PARP (DNA repair) and CD38 consume NAD⁺ — they cleave it into nicotinamide, which must be recycled back via the salvage pathway.
The main cause of NAD⁺ decline is not a lack of precursors — it is the decline of the enzyme NAMPT (nicotinamide phosphoribosyltransferase), which is the key to the salvage pathway. Without functional NAMPT, nicotinamide accumulates, triggers methylation (NNMT) and is excreted in urine. Giving NR/NMN without activating NAMPT = pouring raw materials into a broken factory.
NAD⁺ is a large, charged molecule — cells struggle to absorb it from the extracellular space. A 2024 pre-print study showed that IV NAD increased neutrophils, cytokines and inflammatory response. Direct clinical studies on outcome parameters are virtually non-existent (only 2 studies on intracellular levels). Anecdotal benefits cannot be ruled out, but mechanistic data are unfavourable. If you use NAD IV, supplement with methyl donors (TMG, SAMe) and caffeine (NAMPT activation).
Exercise and fasting naturally activate NAMPT via AMPK. Supplements complement, not replace these signals. Chronic sedentary behaviour and overeating are the primary drivers of NAMPT decline in the population.
Aerobic and strength training activate AMPK → NAMPT. Min. 4× per week.
16:8 or longer — metabolic stress → ↑NAMPT → ↑NAD⁺.
Hormetic stress → mitochondrial biogenesis, synergistic with NAD⁺.
NAD⁺ regulates CLOCK/BMAL1 → circadian rhythm. Quality sleep maintains levels in return.
Reduce CD38 activation. Omega-3, curcumin, leafy greens.
Activates NAMPT — hence sometimes given before NAD IV. 1–2 cups in the morning.