28 peer-reviewed studies · Evidence score: 7.2/10
Martens CR et al. • Nature communications (2018)
Chronic supplementation with the NAD+ precursor vitamin, nicotinamide riboside (NR), is well tolerated and effectively stimulates NAD+ metabolism in healthy middle-aged and older adults.
Conze D et al. • Scientific reports (2019)
Consumption of 100, 300 and 1000 mg NR dose-dependently and significantly increased whole blood NAD+ (i.e., 22%, 51% and 142%) and other NAD+ metabolites within 2 weeks.
Brakedal B et al. • Cell metabolism (2022)
NR treatment was well tolerated and led to a significant, but variable, increase in cerebral NAD levels and related metabolites in the cerebrospinal fluid, with NR recipients showing increased brain NAD levels exhibiting altered cerebral metabolism associated with mild clinical improvement.
Berven H et al. • Nature communications (2023)
High-dose NR up to 3000 mg/day was safe and well-tolerated in Parkinson's disease patients over the 30-day trial period.
Prokopidis K et al. • Journal of cachexia, sarcopenia and muscle (2025)
NAD+ precursor supplementation with NMN and NR shows potential for supporting skeletal muscle mass and function in aging populations.
Elhassan YS et al. • Cell reports (2019)
NR supplementation augments the NAD+ metabolome in aged human skeletal muscle and induces transcriptomic signatures consistent with anti-inflammatory and mitochondrial repair responses.
McDermott MM et al. • Nature communications (2024)
Nicotinamide riboside supplementation elevated NAD+ levels in patients with peripheral artery disease but did not significantly improve the primary walking performance endpoint compared to placebo.
Dollerup OL et al. • The American journal of clinical nutrition (2018)
NR supplementation was safe and well-tolerated in obese men and increased NAD+ metabolites, but did not significantly improve insulin sensitivity or lipid metabolism vs. placebo over 12 weeks.
Christen S et al. • Nature metabolism (2026)
NR, NMN, and niacin each elevated blood NAD+ through distinct metabolic routes with differential effects on the gut microbiome and peripheral NAD+ metabolome.
Norheim KL et al. • Nature aging (2024)
NR supplementation reduced markers of airway inflammation in COPD patients, suggesting NAD+ repletion may attenuate inflammatory pathology in chronic obstructive pulmonary disease.
Dellinger RW et al. • Hepatology (2023)
NRPT supplementation significantly reduced markers of hepatic inflammation in patients with non-alcoholic fatty liver disease, providing the first clinical evidence for NAD+ therapy in NAFLD.
Gallagher C et al. • Ageing research reviews (2026)
NAD+ precursor supplementation demonstrates consistent safety and NAD+ elevation in clinical trials, though functional benefits require larger and longer-duration studies to confirm.
Orr ME et al. • GeroScience (2024)
NR significantly increased blood NAD+ concentrations (2.6-fold) in older adults with mild cognitive impairment, was well tolerated, and was associated with a modest reduction in epigenetic age.
Remie CME et al. • The American journal of clinical nutrition (2020)
NR supplementation increased skeletal muscle acetylcarnitine concentrations and modestly altered body composition in healthy obese adults, suggesting metabolic effects beyond simple NAD+ elevation.
Braidy N et al. • Experimental gerontology (2020)
Most studies indicated that the NAD+ precursors NAM, NR, NMN, and to a lesser extent NAD+ and NADH had a favourable outcome on several age-related disorders associated with the accumulation of chronic oxidative stress, inflammation and impaired mitochondrial function.
Vreones M et al. • Aging cell (2023)
Oral NR supplementation raised blood NAD+ and was associated with reductions in biomarkers of neurodegenerative pathology in plasma extracellular vesicles of neuronal origin.
Shoji M et al. • Aging cell (2025)
NR supplementation improved clinical outcomes in Werner syndrome patients, a progeroid syndrome driven by DNA repair deficiency, supporting the role of NAD+ in genomic stability.
Ahmadi A et al. • JCI insight (2023)
Both CoQ10 and NR were well-tolerated in CKD patients and produced distinct but complementary metabolic effects, with NR robustly elevating NAD+ in this vulnerable population.
Jensen JB et al. • JCI insight (2022)
NRPT supplementation did not significantly attenuate experimental muscle injury in elderly individuals, despite robust NAD+ elevation, suggesting the NAD+ pathway alone may be insufficient for acute muscle repair.
Dollerup OL et al. • The Journal of physiology (2020)
Despite robust NAD+ elevation, NR supplementation did not alter skeletal muscle mitochondrial respiration, content, or morphology in obese, insulin-resistant men over 12 weeks.