Longevity supplement
NAD+ (nicotinamide adenine dinucleotide) is an essential cellular coenzyme whose levels decline with age. Two precursors — nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN) — are widely promoted to restore NAD+ and support sirtuin-mediated longevity pathways. NR is FDA-GRAS and sold as a dietary supplement (e.g., Tru Niagen). NMN is in regulatory limbo: the FDA stated that NMN is excluded from the dietary supplement definition under DSHEA because it was first authorized for investigation as a new drug. Human trials for both precursors show NAD+ biomarker increases, but clinical outcome benefits (insulin sensitivity, physical function) remain inconsistent and no human lifespan data exists.
Track regulatory status (especially FDA NMN/DSHEA determination), clinical trials, and sirtuin research. Do not publish dosing, sourcing, or treatment instructions. Separate biomarker increases from clinical outcome claims.
NAD+ is an essential coenzyme that declines with age in multiple tissues. Foundational reviews (Imai & Guarente, 2010; Verdin et al., 2016) link NAD+ decline to reduced sirtuin activity and propose precursor supplementation as a strategy to address aging biology.
Nicotinamide riboside (NR) has FDA GRAS (Generally Recognized As Safe) status (GRN 733, 2016) and is sold as a dietary supplement, most prominently as Tru Niagen. Human trials show NR reliably raises blood NAD+.
NMN (nicotinamide mononucleotide) is subject to an FDA determination that it is excluded from the dietary supplement definition under DSHEA because it was first authorized for investigation as a new drug. This has caused marketplace disruption, with some retailers withdrawing NMN products.
A randomized controlled trial showed NMN increased muscle insulin sensitivity in prediabetic women (Yoshino et al., Science, 2021). However, a 12-week NR trial in obese men raised NAD+ but did not improve insulin sensitivity or body composition (Dollerup et al., 2018), illustrating the gap between biomarker and clinical outcomes.
No human lifespan or healthspan outcome trial has been completed for NR or NMN. Preclinical mouse studies (Mills et al., 2017) showed NMN mitigated age-related physiological decline but did not demonstrate lifespan extension.
Evidence level: Peer reviewed
Sources: Trends in Pharmacological Sciences / Cell Press, Science / AAAS, American Journal of Clinical Nutrition
Biomarker increases are well established. Do not equate raised NAD+ with proven clinical benefit.
Evidence level: Peer reviewed
Sources: Science / AAAS
Cite the Yoshino et al. (2021) trial. Note that the effect was seen in a specific subgroup (prediabetic women) and requires replication. It is not a lifespan outcome.
Evidence level: Primary regulatory
Sources: U.S. Food and Drug Administration, U.S. Food and Drug Administration
This is the key regulatory distinction. The FDA NMN/DSHEA determination is the reason this page is classified as 'Regulatory watch.' Re-check the FDA advisory list on each review cycle.
Evidence level: Community discussion
Sources: Science / AAAS, Cell Metabolism / Cell Press, ClinicalTrials.gov / U.S. National Library of Medicine
Track as high-attention consumer signal. David Sinclair's prominence amplifies public interest, but his advocacy is distinct from the published clinical evidence base. Preclinical mouse data does not establish human benefit.
Source records are stored in the repo and linked from each claim.
Foundational review (Imai & Guarente) describing how NAD+ links metabolism to sirtuin activity, and proposing NAD+ decline as a driver of aging biology.
High-profile review (Verdin et al., including David Sinclair as a co-author) describing the decline of NAD+ with age and the rationale for supplementation with precursors (NR, NMN).
FDA GRAS (Generally Recognized As Safe) notice response for nicotinamide riboside (NR) chloride, the ingredient in Tru Niagen, supporting its use as a dietary supplement ingredient.
FDA determination that NMN (nicotinamide mononucleotide) is excluded from the dietary supplement definition under DSHEA because it was first authorized for investigation as a new drug. This triggered marketplace disruption for NMN supplements.
ClinicalTrials.gov search showing registered interventional trials of NMN in human subjects, including studies of NAD+ biomarkers, insulin sensitivity, and physical function in older adults.
Randomized, placebo-controlled trial (Yoshino et al., including Shin-ichiro Imai) showing that 10 weeks of NMN supplementation increased muscle insulin sensitivity in prediabetic women. A key human proof-of-concept study.
Randomized, double-blind trial (Dollerup et al.) showing that NR safely increased blood NAD+ in obese men but did not improve insulin sensitivity or body composition over 12 weeks, illustrating the biomarker-vs-outcome gap.
Preclinical study (Mills et al., Sinclair lab) showing that 12 months of NMN administration mitigated age-related decline in multiple physiological parameters in mice, but no lifespan extension.
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