NR (Nicotinamide Riboside)

Nicotinamide adenine dinucleotide (NAD⁺) declines with age, motivating "NAD⁺-boosting" strategies ranging from lifestyle interventions to supplementation with NAD⁺ precursors (e.g., nicotinamide riboside [NR], nicotinamide mononucleotide [NMN]) and, in some wellness settings, parenteral NAD⁺ administration. We conducted a PRISMA-guided systematic review of peer-reviewed human and rodent intervention studies (January 2010-October 2025) evaluating NAD-related compounds administered orally or parenterally. We identified 113 eligible studies: 33 human intervention studies (28 randomized; 5 nonrandomized) and 80 rodent studies. In rodent models, NAD⁺ augmentation was frequently associated with improvements in metabolic, mitochondrial, inflammatory, and functional outcomes, although effects varied across models and endpoints. In humans, oral NR and NMN consistently demonstrated biochemical target engagement (circulating (plasma/whole blood) or cellular (e.g., PBMC) NAD-related metabolites) and were generally well tolerated over weeks to months; however, effects on functional, metabolic, vascular, and other healthspan-relevant outcomes were heterogeneous and often null or endpoint-specific. No eligible outcomes trials evaluated intravenous or intramuscular NAD⁺ itself for anti-aging or wellness indications. One nonrandomized intravenous NMN study met inclusion criteria and primarily contributed short-term safety and biomarker information. An intravenous NAD⁺ pharmacokinetic pilot lacking eligible clinical outcomes was identified as contextual evidence only. Overall, NAD⁺ augmentation shows clear biological activity, but clinical effectiveness for anti-aging or wellness outcomes remains inconclusive. Larger, well-designed randomized trials with longer follow-up and prespecified clinically meaningful endpoints are needed, particularly for parenteral approaches.

INTRODUCTION: Sarcopenia is associated with the loss of skeletal muscle function and mass. Nicotinamide precursors, such as nicotinamide mononucleotide (NMN) and nicotinamide riboside (NR), have received attention for their potential to improve NAD+ levels and mitigate age-related sarcopenia in preliminary models, though evidence on their effects in older adults remains inconclusive. METHODS: We searched PubMed, Cochrane Library, Web of Science, and Scopus to identify randomized controlled trials (RCTs), comparing NR or NMN vs. placebo. A random-effects meta-analysis was employed to determine their impact on measures of sarcopenia such as skeletal muscle index (SMI), handgrip strength (HGS) and gait speed. A narrative synthesis was used for 5-time chair stand test (5CST), short physical performance battery (SPPB), timed-up-and-go (TUG), 6-min walking distance (6MWD), leg and chest press 80% 1RM (repetition maximum) and thigh muscle mass. RESULTS: Included participants had a mean age range from 60.9 to 83 years. NMN supplementation showed no significant effects on SMI (n = 3; mean difference (MD): -0.42, 95% confidence interval (CI): -0.99 - 0.14, I2 = 63%, p = 0.14), HGS (One study estimating left grip; n = 5; MD: 0.61, 95%CI: -0.89 - 2.10, I2 = 0%, p = 0.42; One study estimating right grip; n = 5; MD: 0.45, 95%CI: -1.06 - 1.96, I2 = 0%, p = 0.56), gait speed (n = 4; MD: -0.01, 95%CI: -0.08 - 0.06, I2 = 0%, p = 0.79), or 5CST (n = 2; MD: -0.21, 95%CI: -0.70 - 0.29, I2 = 11%, p = 0.41). Additionally, our narrative synthesis showed that NMN did not improve knee extension strength, SPPB, or thigh muscle mass. NR supplementation was associated with a longer 6MWD among individuals with peripheral artery disease. However, lower scores in the SPPB and slower 5CST were observed in those with mild cognitive impairment. CONCLUSIONS: Current evidence does not support NMN and NR supplementation for preserving muscle mass and function in adults with mean age of over 60 years. Future research should explore supplementation dosage, NAD+ baseline deficiency, and combined interventions. © 2025 The Author(s). Journal of Cachexia, Sarcopenia and Muscle published by Wiley Periodic

BACKGROUND: Alzheimer's disease (AD) is a progressive neurocognitive disorder. There is no cure for AD. Maintenance on intracellular levels of nicotinamide adenine dinucleotide (NAD+) has been reported to be a promising therapeutic strategy for the treatment of AD. NAD+ precursors that represent candidate targets include nicotinamide mononucleotide (NMN) and nicotinamide riboside (NR). OBJECTIVE: This systematic review provides insights into the potential therapeutic value of NAD+ precursors including NMN and NR, for the treatment of AD using preclinical and clinical studies published in the last 5 years. METHODS: The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) protocol was followed to systematically search the literature using two databases. RESULTS: We found 3 studies that used NMN to treat AD in preclinical murine models. However, human clinical trials using NMN as a therapeutic intervention in AD was not available in the current literature. We also found 4 studies that investigated the potential benefits of NR for the treatment of AD in preclinical models. We also found 2 human clinical trials that showed marked improvements in plasma and neuroimaging biomarkers, and cognitive measures following supplementation with NR. CONCLUSIONS: Results of preclinical and clinical studies confirm the potential benefits of NAD+ precursors for the treatment of AD. However, further clinical studies are required to confirm the increasingly important value of NAD+ precursors as effective pharmacological interventions in the clinic.

BACKGROUND: To date, the mitochondrial function has been related to several pathways involved in the cellular aging process. Dietary supplements might have reciprocal and multilevel interactions with mitochondria network; however, no systematic review assessed the role of different nutraceuticals in mitochondria modification of healthy older adults. AIM: To assess the effects of different dietary supplements on mitochondria modifications in older adults. METHODS: On February 22, 2022, PubMed, Scopus, Web of Science, and Cochrane were systematically searched from inception for randomized controlled trials (RCTs). According to PICO model, we considered healthy older adults as participants, nutraceutical treatment as intervention, any treatment as comparator, mitochondrial modifications as outcome. Jadad scale was used for the quality assessment. RESULTS: Altogether, 8489 records were identified and screened until 6 studies were included. A total of 201 healthy older adults were included in the systematic review (mean age ranged from 67.0 ± 1.0 years to 76.0 ± 5.6 years). The dietary supplements assessed were sodium nitrite, N-3 polyunsaturated fatty acids, hydrogen-rich water, nicotinamide riboside, urolithin A, and whey protein powder. Positive effects were reported in terms of mitochondrial oxidative and antioxidant capacity, volume, bioenergetic capacity, and mitochondrial transcriptome based on the nutritional supplements. The quality assessment underlined that all the studies included were of good quality. DISCUSSION: Although dietary supplements might provide positive effects on mitochondria modifications, few studies are currently available in this field. CONCLUSION: Further studies are needed to better elucidate the reciprocal and multilevel interactions between nutraceuticals, mitochondria, and environmental stressors in healthy older adults. © 2022. The Author(s), under exclusive licence to Springer Nature Switzerland AG.

Metabolic alterations shared between the nervous system and skin fibroblasts have emerged in amyotrophic lateral sclerosis (ALS). Recently, we found that a subgroup of sporadic ALS (sALS) fibroblasts (sALS1) is characterized by metabolic profiles distinct from other sALS cases (sALS2) and controls, suggesting that metabolic therapies could be effective in sALS. The metabolic modulators nicotinamide riboside and pterostilbene (EH301) are under clinical development for the treatment of ALS. Here, we studied the transcriptome and metabolome of sALS cells to understand the molecular bases of sALS metabotypes and the impact of EH301. Metabolomics and transcriptomics were investigated at baseline and after EH301 treatment. Moreover, weighted gene coexpression network analysis (WGCNA) was used to investigate the association of the metabolic and clinical features. We found that the sALS1 transcriptome is distinct from sALS2 and that EH301 modifies gene expression differently in sALS1, sALS2 and the controls. Furthermore, EH301 had strong protective effects against metabolic stress, an effect linked to the antiinflammatory and antioxidant pathways. WGCNA revealed that the ALS functional rating scale and metabotypes are associated with gene modules enriched for the cell cycle, immunity, autophagy and metabolic genes, which are modified by EH301. The meta-analysis of publicly available transcriptomic data from induced motor neurons by Answer ALS confirmed the functional associations of genes correlated with disease traits. A subset of genes differentially expressed in sALS fibroblasts was used in a machine learning model to predict disease progression. In conclusion, multiomic analyses highlighted the differential metabolic and transcriptomic profiles in patient-derived fibroblast sALS, which translate into differential responses to the investigational drug EH301. © The Author(s) 2022. Published by Oxford University Press. All rights reserved. For Permissions, please email: [email protected].

Nicotinamide adenine dinucleotide (NAD+) is an essential pyridine nucleotide that is present in all living cells. NAD+ acts as an important cofactor and substrate for a multitude of biological processes including energy production, DNA repair, gene expression, calcium-dependent secondary messenger signalling and immunoregulatory roles. The de novo synthesis of NAD+ is primarily dependent on the kynurenine pathway (KP), although NAD+ can also be recycled from nicotinic acid (NA), nicotinamide (NAM) and nicotinamide riboside (NR). NAD+ levels have been reported to decline during ageing and age-related diseases. Recent studies have shown that raising intracellular NAD+ levels represents a promising therapeutic strategy for age-associated degenerative diseases in general and to extend lifespan in small animal models. A systematic review of the literature available on Medline, Embase and Pubmed was undertaken to evaluate the potential health and/or longevity benefits due to increasing NAD+ levels. A total of 1545 articles were identified and 147 articles (113 preclinical and 34 clinical) met criteria for inclusion. Most studies indicated that the NAD+ precursors NAM, NR, nicotinamide mononucleotide (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. While these compounds presented with a limited acute toxicity profile, evidence is still quite limited and long-term human clinical trials are still nascent in the current literature. Potential risks in raising NAD+ levels in various clinical disorders using NAD+ precursors include the accumulation of putative toxic metabolites, tumorigenesis and promotion of cellular senescence. Therefore, NAD+ metabolism represents a promising target and further studies are needed to recapitulate the preclinical benefits in human clinical trials. Crown Copyright © 2020. Published by Elsevier Inc. All rights reserved.

BACKGROUND: Friedreich's ataxia is a rare, chronic, progressive, neurodegenerative condition affecting multiple organ systems, including neurological, musculoskeletal, cardiac, and endocrine systems, and is marked by low cardiopulmonary fitness. We tested the effect of exercise and NAD+ precursor supplementation with nicotinamide riboside, which have each shown benefits in animal and early clinical studies, on cardiopulmonary fitness in individuals with Friedreich's ataxia. METHODS: This 12-week, outpatient, phase 2, single-site (Children's Hospital of Philadelphia, Philadelphia, PA, USA), randomised, 2 × 2 factorial clinical trial recruited individuals aged 10-40 years with an ejection fraction of 45% or greater who were able to exercise. A computer-generated randomisation sequence was developed by the trial statistician. Random allocation was age-stratified (<18 years vs ≥18 years) to one of four groups: placebo and no exercise with attention control (weekly phone calls; henceforth placebo only), nicotinamide riboside and no exercise with attention control (henceforth nicotinamide riboside only), placebo and exercise (exercise only), and nicotinamide riboside and exercise (combination therapy). Individualised exercise plans were developed by the exercise physiologist (three aerobic and two resistance training sessions weekly), performed at the individual's home, and overseen remotely (telephone check-ins by the physiologist). Weight-based dosing of nicotinamide riboside or placebo was 300 mg (1 capsule) for weights of 24 kg up to 48 kg, 600 mg (2 capsules) for weight 48 kg up to 72 kg, and 900 mg (3 capsules) for weights of over 72 kg. The primary outcome was change in peak VO2 (L/min) during cardiopulmonary exercise testing at 12 weeks versus baseline, and the effect of treatment group was assessed in a statistical model accounting for age (stratification variable), sex, and baseline peak VO2. Stage 1 analysis tested the difference between each active treatment versus the control group, and stage 2 analysis (if combination therapy was effective) tested the difference between combination treatment and exercise alone; family-wise type 1 error was maintained <0·

LRRK2 (encoding leucine-rich repeat kinase 2) variants are the most common genetic cause of Parkinson's disease (PD). Lowering LRRK2 levels and/or inhibiting LRRK2 activity may modify PD-associated neuropathology. BIIB094 (ION859), an antisense oligonucleotide, targets LRRK2 mRNA for degradation. REASON was a first-in-human randomized phase 1 study investigating the safety, tolerability, pharmacokinetics and pharmacodynamics of intrathecal BIIB094 in patients with PD. In part A, 40 participants received single doses of BIIB094 10-150 mg or placebo. In part B, 42 participants, stratified by LRRK2 variant status, received four doses of BIIB094 40-120 mg or placebo every 4 weeks. Adverse events were reported by 64.5% (20/31) of participants in part A and by 84.8% (28/33) of participants in part B. The events were mainly mild to moderate and not dose limiting. No serious adverse events related to BIIB094 were reported in either part A or B. Systemic BIIB094 exposure increased with dose. Cerebrospinal fluid (CSF) LRRK2 and phosphorylated Rab10 levels were lowered by up to 59% and up to 50%, respectively, irrespective of LRRK2 variant status. Concomitant reductions in CSF lysosomal protein levels suggested a potential mechanism whereby LRRK2 therapeutics may impact underlying PD pathophysiology. ClinicalTrials.gov identifier, NCT03976349 ; EudraCT number, 2018-002995-42. © 2026. The Author(s), under exclusive licence to Springer Nature America, Inc.

Nicotinamide adenine dinucleotide (NAD(H)) and its phosphorylated form NADP(H) are vitamin B3-derived redox cofactors essential for numerous metabolic reactions and protein modifications. Various health conditions are associated with disturbances in NAD+ homeostasis. To restore NAD+ levels, the main biosynthetic pathways have been targeted, with nicotinamide (Nam), nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN) being the most prominent boosters. However, while many preclinical studies have examined the effects of these precursors, a direct comparison in humans is lacking, and recent rodent research suggests that the NAD+-boosting effects of NR and NMN may depend on their microbial conversion to nicotinic acid (NA), a mechanism not yet confirmed in humans. Here we show in a randomized, open-label, placebo-controlled study in 65 healthy participants that 14 days of supplementation with NR and NMN, but not Nam, comparably increases circulatory NAD+ concentrations in healthy adults. Unlike the chronic effect, only Nam acutely and transiently affects the whole-blood NAD+ metabolome. Using ex vivo fermentation with human microbiota, we identify that NR and NMN give rise to NA and specifically enhance microbial growth and metabolism. We further demonstrate ex vivo in whole blood that NA is a potent NAD+ booster, while NMN, NR and Nam are not. Ultimately, we propose a gut-dependent model for the modes of action of the three NAD+ precursors with NR and NMN elevating circulatory NAD+ via the Preiss-Handler pathway, while rapidly absorbed Nam acutely affects NAD+ levels via the salvage pathway. Overall, these results indicate a dual effect of NR and NMN and their microbially produced metabolite NA: a sustained increase in systemic NAD+ levels and a potent modulator of gut health. ClinicalTrials.gov identifier: NCT05517122 . © 2026. The Author(s).

BACKGROUND AND AIMS: Recent preclinical studies have shown that nicotinamide adenine dinucleotide (NAD+) plays a critical role in molecular mechanisms of axon degeneration, and reductions in NAD+ levels are associated with axonal degeneration. Nicotinamide riboside (NR) is a safe and widely available pyridine-nucleoside form of vitamin B3 and is an NAD+ precursor. METHODS: To investigate if oral supplementation of synthetic NR can act as a therapeutic agent to prevent degeneration of small somatic sensory axons innervating the skin or promote regeneration of these same fibers in humans, we utilized a validated experimental model of cutaneous nerve degeneration and regeneration and conducted a placebo-controlled, double-blinded Phase 2 study. RESULTS: NR supplementation did not result in elevation of plasma NAD+ levels but resulted in a small increase in NAD+ in the skin samples. NR supplementation did not prevent capsaicin-induced degeneration of the epidermal sensory nerve fibers, and there was no difference in the amount of epidermal reinnervation at the 90-day visit. Although there was a small but statistically significant increase in the number of epidermal sensory nerve fibers at the 60-day visit, these results are preliminary and will need to be validated in larger studies. INTERPRETATION: At present oral NR supplementation, at the doses used in this study, cannot be recommended to prevent neuropathy or to improve nerve regeneration. © 2026 Peripheral Nerve Society.

Aerobic exercise lowers blood pressure (BP) with varying effects in hypertensive adults, potentially due to age-related nicotinamide adenine dinucleotide (NAD) metabolism dysregulation. This pilot randomized clinical trial (RCT) tested the efficacy of combining aerobic exercise with the NAD booster nicotinamide riboside (NR) to enhance BP control. In this double-blinded RCT, 54 sedentary adults (≥ 55 years) with mean daytime systolic BP (SBP) ≥ 130 mmHg were randomized to 6 weeks of 1000 mg/day of NR combined with 3 days/week of supervised 30-min walking exercise (NR + Ex), Placebo combined with the same exercise regimen (PL + Ex), or NR alone (NR). The primary outcome was daytime SBP. Other outcomes included pulse wave velocity (PWV), NAD catabolites, and nighttime BP. The primary comparison was between NR + Ex and PL + Ex. Of 54 participants (mean age 67 years, 61% female), 49 (NR + Ex: n = 15, PL + Ex: n = 16, NR: n = 18) completed all study visits (93% adherence to exercise and 90% to supplementation). NR + Ex (mean change = 5.19 ± 13.2 mmHg) did not reduce SBP more than PL + Ex (- 2.71 ± 10.5 mmHg). NR + Ex (- 0.31 ± 0.77 m/s) showed a trend toward a greater reduction in PWV. Levels of NAD catabolites were higher in NR groups. In a post hoc analysis, NR + Ex showed a trend toward greater nighttime BP reductions (systolic: - 9.6 ± 9.22; diastolic: - 4.51 ± 7.12 mmHg) in participants without antihypertensive medications. NR + Ex was not superior to PL + Ex in reducing BP in hypertensive middle-aged and older. However, trends toward greater nighttime BP reduction in NR + Ex in participants without antihypertensive medication warrant further investigation in a Phase IIb RCT. © 2025. The Author(s).

Werner syndrome (WS) is a rare hereditary progeroid syndrome caused by mutations in the WRN gene. Patients frequently develop various age-associated diseases prematurely, often leading to early mortality (≤ 60 years of age). Depletion of nicotinamide adenine dinucleotide (NAD)+ has been reported in patients with WS, suggesting a key role in the pathogenesis of WS. NAD+ supplementation may improve the condition of WS and other accelerated aging diseases. Therefore, we conducted a double-blind, randomized, crossover, placebo-controlled trial in patients with WS to evaluate the safety and efficacy of the NAD+ precursor, nicotinamide riboside (NR). NR (1000 mg) or placebo capsules were self-administered once daily for 26 weeks, followed by a crossover to the opposite arm for another 26 weeks. The primary endpoint was the safety of NR. Secondary endpoints included NAD+ levels in plasma, number, and size of skin ulcers, blood examinations, sarcopenia, heel pad thickness, cardio-ankle vascular index (CAVI), and ankle-brachial index. The exploratory endpoints involved metabolome profiles of plasma. No serious adverse events were observed during NR treatment. Importantly, CAVI improved, the skin ulcer area decreased, and heel pad thinning showed a declining trend. Metabolomic analysis revealed a significant decrease in blood creatinine. NR treatment significantly improved arterial stiffness, as indicated by CAVI, and likely suppressed renal functional decline in patients with WS. Therefore, NR may be beneficial for preventing atherosclerosis, skin ulcers, and kidney dysfunction in patients with WS. © 2025 The Author(s). Aging Cell published by Anatomical Society and John Wiley & Sons Ltd.

Chronic obstructive pulmonary disease (COPD) is a progressive, incurable disease associated with smoking and advanced age, ranking as the third leading cause of death worldwide. DNA damage and loss of the central metabolite nicotinamide adenine dinucleotide (NAD+) may contribute to both aging and COPD, presenting a potential avenue for interventions. In this randomized, double-blind, placebo-controlled clinical trial, we treated patients with stable COPD (n = 40) with the NAD+ precursor nicotinamide riboside (NR) for 6 weeks and followed-up 12 weeks later. The primary outcome was change in sputum interleukin-8 (IL-8) from baseline to week 6. The estimated treatment difference between NR and placebo in IL-8 after 6 weeks was -52.6% (95% confidence interval (CI): -75.7% to -7.6%; P = 0.030). This effect persisted until the follow-up 12 weeks after the end of treatment (-63.7%: 95% CI -85.7% to -7.8%; P = 0.034). For secondary outcomes, NR treatment increased NAD+ levels by more than twofold in whole blood, whereas IL-6 levels in plasma remained unchanged. In exploratory analyses, treatment with NR showed indications of upregulated gene pathways related to genomic integrity in the airways and reduced epigenetic aging, possibly through a reduction in cellular senescence. These exploratory analyses need to be confirmed in future trials. ClinicalTrials.gov identifier: NCT04990869 . © 2024. The Author(s).

BACKGROUND: Childhood cancer survivors (CCS) have a 50% higher risk of diabetes mellitus (DM) compared with the general population. Interventions in survivors with prediabetes (fasting glucose 100-125 mg/dL or hemoglobin A1c 5.7%-6.4%) may mitigate the development of DM and its attendant morbidity, but there is limited information on the feasibility of secondary prevention in this setting. METHODS: This 6-week pilot feasibility 1:1 randomized controlled trial enrolled 20 CCS on a structured telehealth exercise program ± nicotinamide riboside (NR), a nicotinamide adenine dinucleotide precursor. Feasibility metrics were: (1) ≥50% of eligible CCS enrolled onto study; (2) ≥70% of participants completed baseline and end-of-study assessments; (3) ≥70% compliance with exercise and NR. Secondary endpoints included changes in biomarkers associated with glucose homeostasis and muscle health. RESULTS: Median age (years) at cancer diagnosis was 16.5 (range, 1.5-21.5) and 35.5 (range, 18.0-67.0) at study enrollment. Enrollment rate was 87%, and 85% of participants completed baseline and end-of-study assessments. The mean percentage of exercise sessions completed was 86.6%; NR compliance was > 90%. There were no severe adverse events attributable to study interventions. Secondary endpoints were not significantly different between study arms at study completion. Myostatin decrease was observed in participants who completed a higher median number of exercise sessions and was associated with decreased intramuscular adipose tissue and increased lower extremity muscle cross-sectional area. CONCLUSIONS: A telehealth exercise intervention ± NR supplementation was feasible in CCS with prediabetes. Future studies in larger cohorts may be needed to evaluate their beneficial effects on muscle health and DM risk among CCS. © 2024 Wiley Periodicals LLC.

Erratum in Nat Commun. 2024 Aug 12;15(1):6890. doi: 10.1038/s41467-024-51289-7. People with lower extremity peripheral artery disease (PAD) have increased oxidative stress, impaired mitochondrial activity, and poor walking performance. NAD+ reduces oxidative stress and is an essential cofactor for mitochondrial respiration. Oral nicotinamide riboside (NR) increases bioavailability of NAD+ in humans. Among 90 people with PAD, this randomized double-blind clinical trial assessed whether 6-months of NR, with and without resveratrol, improves 6-min walk distance, compared to placebo, at 6-month follow-up. At 6-month follow-up, compared to placebo, NR significantly improved 6-min walk (+7.0 vs. -10.6 meters, between group difference: +17.6 (90% CI: + 1.8,+∞). Among participants who took at least 75% of study pills, compared to placebo, NR improved 6-min walk by 31.0 meters and NR + resveratrol improved 6-min walk by 26.9 meters. In this work, NR meaningfully improved 6-min walk, and resveratrol did not add benefit to NR alone in PAD. A larger clinical trial to confirm these findings is needed. © 2024. The Author(s).

Nicotinamide adenine dinucleotide (NAD) replenishment therapy using nicotinamide riboside (NR) shows promise for Parkinson's disease (PD) and other neurodegenerative disorders. However, the optimal dose of NR remains unknown, and doses exceeding 2000 mg daily have not been tested in humans. To evaluate the safety of high-dose NR therapy, we conducted a single-center, randomized, placebo-controlled, double-blind, phase I trial on 20 individuals with PD, randomized 1:1 on NR 1500 mg twice daily (n = 10) or placebo (n = 10) for four weeks. The trial was conducted at the Department of Neurology, Haukeland University Hospital, Bergen, Norway. The primary outcome was safety, defined as the frequency of moderate and severe adverse events. Secondary outcomes were tolerability defined as frequency of mild adverse events, change in the whole blood and urine NAD metabolome, and change in the clinical severity of PD, measured by MDS-UPDRS. All 20 participants completed the trial. The trial met all prespecified outcomes. NR therapy was well tolerated with no moderate or severe adverse events, and no significant difference in mild adverse events. NR therapy was associated with clinical improvement of total MDS-UPDRS scores. However, this change was also associated with a shorter interval since the last levodopa dose. NR greatly augmented the blood NAD metabolome with up to 5-fold increase in blood NAD+ levels. While NR-recipients exhibited a slight initial rise in serum homocysteine levels, the integrity of the methyl donor pool remained intact. Our results support extending the dose range of NR in phase II clinical trials to 3000 mg per day, with appropriate safety monitoring. Clinicaltrials.gov identifier: NCT05344404. © 2023. The Author(s).

As the global population ages rapidly, delaying and preventing age-related diseases have become urgent priorities in public health and biomedical research. During aging, mitochondrial dysfunction is a core molecular hallmark and a common pathogenic mechanism underlying multiple age-related disorders. Age-related mitochondrial dysfunction typically manifests as diminished metabolic capacity, impaired organelle renewal, and disrupted redox homeostasis. These factors interact to form a feedback loop constraining mitochondrial adaptability. Specifically, the interdependent decline in NAD+ availability, impaired mitochondrial biogenesis, and excessive oxidative stress render single-pathway interventions ineffective in mitigating systemic functional impairments triggered by aging. To address this complex mechanism, this review presents a novel tri-axis anti-aging model encompassing three key compounds: nicotinamide mononucleotide/nicotinamide riboside (NMN/NR), pyrroloquinoline quinone (PQQ), and l-ergothioneine (EGT). Within this framework, NMN/NR serves as a broad NAD+-dependent regulator of mitochondrial homeostasis, with its most immediate effects on metabolic activation, while PQQ and EGT may further strengthen mitochondrial remodeling and redox resilience, respectively. While each compound has distinct functional emphases, they are highly mechanistically coupled, collectively forming a closed-loop network regulating mitochondrial number, function, and homeostasis. This review synthesizes preclinical and emerging clinical evidence supporting the standalone or combined use of NMN/NR, PQQ, and EGT across various diseases. Collectively, by conceptualizing mitochondrial aging as a systemic imbalance rather than isolated molecular defects, this paper highlights a three-axis model of NMN/NR, PQQ, and EGT. This framework offers a theoretical foundation for mitochondrial-targeted anti-aging interventions while laying the groundwork for future clinical research, nutritional interventions, and the development of multi-target combination strategies.

BACKGROUNDEnhancing NAD+ levels with nicotinamide riboside (NR) confers antiinflammatory effects in human disease, although immunoregulatory mechanisms remain poorly characterized. We previously showed that ex vivo NR supplementation of primary CD4+ T cells from psoriatic individuals dampened immune responsiveness.METHODSTo validate this in vivo, we performed a randomized, placebo-controlled NR supplementation study in individuals with mild-to-moderate psoriasis. Participants received oral NR (500 mg twice daily) or matching placebo for 4 weeks, with blood samples collected at baseline and after supplementation. NR reduced Th17 immune responsiveness.RESULTSBulk CD4+ T cell RNA-seq identified induction of the SLIT-ROBO signaling pathway. NR supplementation increased circulating SLIT2 levels and enhanced SLIT2 production in dermal fibroblasts. Pharmacologic and genetic interrogation in CD4+ T cells and fibroblasts demonstrated that SLIT2, acting through the ROBO1 receptor, inhibited Rho GTPase signaling, thereby attenuating canonical Th17 polarization and fibroblast inflammatory activation.CONCLUSIONThese findings indicate that NAD+ augmentation exerts anti-inflammatory effects in psoriasis through SLIT2-ROBO1-mediated crosstalk between dermal fibroblasts and circulating CD4+ T cells, leading to suppression of Th17-driven inflammation.TRIAL REGISTRATIONClinicalTrials.gov NCT04271735 (registration date - 2020-08026), NCT01143454 (registration date - 2010-07-21), NCT01778569 (registration date - 2013-01-22), and NCT00001846 (registration date - 2001-01-11).FUNDINGThe NHLBI Division of Intramural Research (HL005102 - MNS).

Type 2 diabetes is linked to neuropsychiatric complications such as anxiety-like behaviors, disrupted brain metabolism, neuroinflammation, and impaired mitochondrial function. Nicotinamide riboside (NR) has emerged as a potential therapeutic agent for these complications due to its role in NAD + biosynthesis and neuroprotective properties. In this study, we assessed whether NR supplementation can ameliorate anxiety-like behavior in a mouse model of type 2 diabetes by modulating the hippocampal inflammatory response. 8-week-old db/db mice on the BKS background were used as a model of type 2 diabetes, and db/m mice were used as non-diabetic controls. Four groups, consisting of non-diabetic and diabetic mice, were fed with a control diet or a diet supplemented with NR at 500 mg/kg dosage for 20 weeks. The open field test and nesting behavioral assessments were conducted to evaluate anxiety-related behaviors and overall well-being. After animals were euthanized, biochemical analyses were performed on hippocampal samples using RT-qPCR, Western blotting, and immunohistochemistry. Behavioral assessments revealed increased anxiety and reduced nest-building motivation in db/db mice compared with control mice. These effects were ameliorated by NR treatment. Biochemical analyses revealed that NR attenuated markers of inflammation, including astrocytosis and microglial activation, activation of inflammatory signaling via STING and NF-kB, and pro-inflammatory cytokines. Our findings show that NR supplementation reduces anxiety-like symptoms and neuroinflammation in diabetic mice, highlighting the potential therapeutic relevance of NR in mitigating neuropsychiatric complications associated with diabetes mellitus. © 2026. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.

INTRODUCTION: Developing interventions to delay aging and improve lifespan and healthspan is a critical goal in aging research. Individual geroprotective compounds fail to address the complexity, interconnectedness, and dynamic nature of biological systems, limiting success in significantly extending lifespan and improving health. This study investigates the effects of SRN-901-a novel oral combinatorial drug that consists of urolithin A, quercetin, nicotinamide riboside, alpha-lipoic acid, and Seragon's SRN-820-on lifespan extension, frailty reduction, disease-related gene expression pathways, metabolic aging, and the proteome in 18-month-old mice fed a Western diet. RESULTS: SRN-901-treated mice showed a significant increase of 33% in median remaining lifespan compared to placebo-treated mice. Cox proportional hazards analysis revealed a hazard ratio of 0.54, indicating that SRN-901 treatment was associated with a 46% reduction in the hazard of death. While rapamycin increased lifespan in adult mice, nicotinamide mononucleotide (NMN), and nicotinamide riboside (NR) did not show significant differences in median lifespan compared to placebo. SRN-901 protected mice against increased frailty during aging, with baseline-normalized scores rising to 1.17 in treated mice and 1.57 in controls, corresponding to a 70% attenuation of frailty progression between pre-treatment (D-14) and post-treatment (D128; p < 0.001). Transcriptomic analyses revealed that SRN-901 modulates gene expression across pathways implicated in aging biology, including inflammation, apoptosis, and DNA repair, as well as gene sets associated with neurodegenerative disorders, including Alzheimer's disease. Metabolic profiling revealed that SRN-901 was associated with attenuation of several age-related metabolic shifts, resulting in a blood metabolite profile that more closely resembled that of younger mice. The upregulation of glutathione metabolism and other longevity-related pathways underscores SRN-901's role in enhancing cellular defenses against oxidative stress and maintaining metabolic health. DISCUSSION: These results highlight SRN-901 as a promising multi-compound candidate for extending li

Erratum in Pharm Sci Adv. 2026 Oct 08;4:100151. doi: 10.1016/j.pscia.2026.100151. Natural killer (NK) cells play a key role in the standard treatment of diffuse large B-cell lymphoma (DLBCL). However, NK cells in DLBCL patients frequently display an exhausted phenotype, which is associated with poor clinical outcomes. The metabolic mechanisms contributing to this functional impairment remain poorly understood. We assessed degranulation (CD107a), cytokine secretion (IFN-γ, TNF-α), mitochondrial activity, and lipid metabolism in NK cells from DLBCL patients and healthy donors. Dysregulated lipid species were identified by GC-MS lipidomics and validated in NK-92MI and primary NK cells. The functional involvement of CD36 was assessed using the specific inhibitor, with subsequent examination of its correlation with cytotoxic activity. NAD+ metabolism was evaluated via NAMPT and NAD+ levels, and rescue assays involved nicotinamide mononucleotide (NMN). For in vivo validation, a murine lymphoma model was treated with nicotinamide riboside (NR), and tumor-infiltrating NK cell function and lipid accumulation were analyzed. NK cells from DLBCL patients demonstrated significantly reduced proliferative capacity and cytotoxicity, accompanied by substantial lipid accumulation. This dysfunction was linked to upregulated CD36 expression and associated with ferroptosis-a form of regulated necrotic cell death. Mechanistically, CD36-mediated lipid uptake induced metabolic reprogramming and promoted ferroptotic cell death, concurrently depleting intracellular NAD+ levels. Importantly, supplementation with NAD+ precursors effectively reversed NK cell exhaustion and restored antitumor activity both in vitro and in vivo. CD36-driven lipid metabolic disruption leads to NK cell dysfunction and ferroptosis in DLBCL. Thus, restoration of NAD+ levels represents a promising therapeutic strategy to enhance NK cell effector function and improve antitumor immunity in DLBCL. © 2026 The Authors.

Perinatal asphyxia (PA) is a primary cause of neonatal morbidity, with persistent neurological sequelae, associated with mitochondrial dysfunction and redox imbalance. The lack of experimental approaches for region-specific evaluation of mitochondrial bioenergetics in structurally preserved neural tissues has limited the identification of selective vulnerabilities and redox-based therapeutic targets. Here, we introduce a real-time metabolic profiling strategy that integrates Seahorse XFe96 respirometry with Cytation 5 image-based quality control to quantify mitochondrial respiration and glycolytic flux in organotypic cultures derived from distinct brain regions of neonatal rats exposed to global PA. Using this strategy, we demonstrate that PA induces a profound and region-selective impairment of mitochondrial function, characterized by reduced basal, ATP-linked, maximal, and spare respiratory capacity in the substantia nigra and neostriatum, while neocortical bioenergetics remain largely preserved. These alterations are accompanied by a shift toward glycolysis, reflected by increased extracellular acidification rates and reduced OCR/ECAR ratios. Notably, in vivo administration of the NAD⁺ precursor nicotinamide riboside (0.8 mmol·kg⁻¹, i.p., 1 h after birth) effectively prevented PA-induced mitochondrial respiration deficits, attenuated oxidative stress-induced cell death, and preserved regional neurochemical integrity, particularly within the nigrostriatal neurocircuitry. Together, these findings reveal a heterogeneous mitochondrial redox and bioenergetic vulnerability of the developing brain to perinatal hypoxia. This integrated organotypic-metabolic approach may offer novel opportunities to dissect out region-specific mitochondrial dysfunction and to explore NAD⁺-based therapeutic strategies targeting neonatal brain injury.

Nicotinamide adenine dinucleotide (NAD+) is essential for maintaining homeostasis in all types of cells, including endothelium, and depletion of its pool can impair bioenergetics and stress response, contributing to cardiovascular disorders. Nicotinamide riboside (NR) effectively restores the intracellular NAD+ pool, supporting endothelial integrity, but the molecular mechanisms remain incompletely elucidated, particularly regarding extracellular adenine nucleotide catabolism, purinergic signaling, and their effects on immune cell adhesion. In this study, we aimed to investigate the effects of NR on intracellular nucleotides, extracellular adenine nucleotide catabolism, and adhesive properties in the cultured murine (H5V) and human (HMEC-1) microvascular endothelial cell line. We demonstrated that NR treatment significantly increased intracellular NAD+ concentrations without changes in the energy status of endothelial cells. We also showed that NR treatment accelerated extracellular hydrolysis of ATP and AMP and decreased the rate of adenosine deamination in endothelial cells. Moreover, we observed CD73 activity and adenosine-related reduced adhesion of T-lymphocytes, monocytes and platelets to the NR-treated endothelial monolayer. Our findings highlight a previously unrecognized role of NR in maintaining endothelial homeostasis, showing that NR is not only a potent intracellular NAD+ booster in endothelial cells but also affects extracellular nucleotide metabolism in a way that promotes cytoprotective adenosine formation.

Nicotinamide riboside (NR), a natural precursor of NAD⁺, has been suggested to confer protection against metabolic and age-related disorders. However, its effect on chronic kidney disease (CKD), particularly in the context of obesity, remains poorly understood. Here, we evaluated the potential effects of NR supplementation in models of obesity-induced renal injury. The metabolic and renal effects of both preventive and interventional NR supplementation were assessed in mice fed high-fat or low-fat diets. Our data showed that NAD⁺ repletion by NR supplementation, whether preventive or interventional, did not affect body or organ weights, and did not ameliorate glucose metabolism, insulin resistance, or hepatic and renal lipid accumulation. NR supplementation was however associated with SIRT3-mediated deacetylation of SOD2 in the renal tissue of obese mice. It moderately reduced renal dysfunction and was associated with increased mitochondrial content. To further explore the cellular mechanisms underlying the renal effects of NR in a lipotoxic context, we investigated its impact on renal proximal tubular cells exposed to palmitic acid (PA). NR significantly prevented oxidative stress in proximal tubular epithelial cells, as evidenced by the activation of SOD2 as well as the reduction of lipid peroxidation. Moreover, NR improved mitochondrial damage and promoted mitophagy. However, NR did not reduce PA-induced lipid accumulation. In conclusion, this study provides evidence that NR exerts antioxidant effects and enhances mitochondrial function in renal cells in vitro but does not protect obese mice from metabolic disorders and associated CKD.

High-dose ionizing radiation induces severe multi-organ injury, yet no broadly effective, orally available countermeasure has been validated. Here we describe a fully oral, multi-component formulation comprising bioavailable polyphenol derivatives (pterostilbene cocrystals and silybin-phosphatidylcholine), the NAD⁺ precursor nicotinamide riboside, and captopril, an angiotensin-converting enzyme inhibitor with established radiomitigative activity that synergizes with the polyphenols. This combination provides robust systemic radioprotection, enabling long-term survival in 90% of mice exposed to a lethal (LD50/30) dose of X-rays. Mechanistically, the formulation mitigates hematopoietic, intestinal, and neuromotor injury while enhancing DNA repair, suppressing oxidative stress, preserving NAD⁺ homeostasis, and activating autophagy. In intestinal epithelial cells, it markedly reduces radiation-induced apoptosis, inflammatory signaling, and mitochondrial dysfunction through coordinated modulation of Nrf2, NF-κB, and sirtuin-regulated stress responses. Critically, normal tissue protection does not compromise tumor control. In triple-negative breast cancer models, irradiation-induced tumor regression is preserved, whereas in glioblastoma (a typically radioresistant malignancy) tumor radiosensitivity is significantly enhanced via sustained oxidative stress, reduced PARP1 expression, and inhibition of HIF-1α and VEGF signaling. Collectively, these findings define an orally deployable, mechanistically integrated strategy that protects normal tissues while preserving or augmenting tumor radiosensitivity, supporting its translational potential as a practical and effective countermeasure against ionizing radiation exposure.

PURPOSE OF REVIEW: The nicotinamide adenine dinucleotide (NAD + ) is an important redox cofactor that plays a major role in energy metabolism. This review provides an overview of the current understanding of NAD + in cardiovascular diseases. RECENT FINDINGS: Activation of the rate-limiting enzyme nicotinamide phosphoribosyltransferase (NAMPT), a key component of the NAD + salvage pathway, is emerging as an alternative method to replenish the cycling NAD + pools and to alleviate the cardiovascular pathophysiology driven by NAD + depletion. The NAD + -dependent sirtuins play an important role in cellular metabolism and integrate the circadian signaling of clock controlled Nampt oscillation and thereby NAD + synthesis. SUMMARY: An imbalance in the NAD + /NADH ratio caused by NAD + depletion is implicated in various diseases, including metabolic disease, aging, and cancer. The cellular NAD + content is decreased in cardiovascular diseases and heart failure. Lack of NAD + in cardiomyocytes leads to mitochondrial dysfunction, increased reactive oxygen species (ROS) production and cell death. The supplementation of NAD + and its precursors such as nicotinic acid (NA), nicotinamide (NAM), nicotinamide mononucleotide (NMN), and nicotinamide riboside (NR) are currently being evaluated in clinical trials. This review mainly focuses on the role of NAD + in cardiovascular diseases and therapeutics.

Background/Objective: Delaying muscle fatigue could alleviate economic and food security, and welfare concerns associated with transporting market-weight pigs to harvest. Previous research demonstrates barrow nicotinamide riboside (NR) supplementation at varying doses during the last 10 d of finishing shows to be a countermeasure to muscle fatigue by reducing muscle fiber recruitment and increasing mitochondrial DNA expression in a dose-dependent manner. Therefore, this study aims to determine if a greater NR dose further enhances barrow fatigue resistance and characterize muscle mitochondria content and efficiency. Methods: Barrows (N = 87) were assigned to one of two dietary NR supplementation doses (TRT): 0 (0NR) or 150 (150NR) mg/kg body weigh NR administered during the last 14 d of finishing. Muscle (MUS) biopsies were collected on supplementation d (DAY) 0, 7 and 14 from three hind-leg muscles for NAD+ quantification and mitochondrial DNA expression and efficiency. On days 15 and 16, barrows were subjected to a performance test until they were subjectively exhausted. Electromyography data collection during the performance test were divided into five periods (PER) and included normalized root mean square (nRMS) from the same muscles. Results: There were no three-way interaction for nRMS (p > 0.83), but there were MUS × TRT and PER × TRT interactions (p < 0.05). During performance testing, 150NR had greater nRMS than 0NR in the bicep femoris (BF) and tensor fasciae latae (TFL; p < 0.01), but there were no differences in the semitendinosus (ST; p = 0.77). Treatments did not differ during PER 1 and 2 (p > 0.14) but 150NR had greater nRMS than 0NR during PER 3, 4 and 5 (p < 0.01) across all muscles. There was no three-way interaction for normalized (nNAD+; p = 0.14), but there was a DAY × TRT interaction (p < 0.05). There were no differences between 0NR and 150NR at d 0 (p = 0.95); however, by d 7 and 14, 150NR muscles had greater nNAD+ than 0NR muscles (p < 0.01). There tended to be a three-way interaction for mitochondrial DNA expression (p = 0.09). At supplementation d 14, all 150NR muscles had greater mitochondrial DNA expression and electron transport chai

BACKGROUND: Endothelial dysfunction has emerged as early and pivotal event in Alzheimer's disease (AD), yet the molecular mechanisms linking vascular aging to neuroinflammation remain elusive. METHODS: We used APP/PS1 mice and amyloid beta (Aβ)-challenged brain endothelial cells (BECs) to understand the mechanisms of nicotinamide adenine dinucleotide (NAD+) deficiency, and its relationship with endothelial senescence and neuroinflammation in AD pathology. Nicotinamide riboside supplementation was administered to APP/PS1 mice to determine whether restoration of NAD+ homeostasis mitigates AD-related vascular and inflammatory pathology. RESULTS: NAD+ deficiency induced voltage-dependent anion channel 1 (VDAC1) oligomerization, mitochondrial DNA (mtDNA) leakage, and cGAS/STING-IRF3 activation, promoting endothelial senescence and SASP production with NAD+-consuming enzyme CD38 upregulation. Senescent BECs triggered IL-6-dependent microglial activation. NR treatment restored mitochondrial integrity, suppressed cGAS-STING signaling, and reduced neuroinflammation, improving vascular function and cognition. DISCUSSION: Aβ-driven NAD+ deficiency initiates a VDAC1-mtDNA-cGAS/STING cascade that promotes endothelial senescence and neurovascular inflammation in AD pathology, and amplifies neuroinflammation through BEC-microglia crosstalk, highlighting NAD+ restoration as a promising AD therapeutic strategy. © 2026 The Author(s). Alzheimer's & Dementia published by Wiley Periodicals LLC on behalf of Alzheimer's Association.

Background: Alzheimer's disease (AD) remains a major public health challenge. Observational associations between dietary patterns and reduced dementia risk have prompted investigations of dietary bioactives (DBs) as cognitive nutraceuticals. Methods: This critical narrative review examines interventional trials for nine prominent DBs relevant to AD: docosahexaenoic acid (DHA), curcumin, resveratrol, epigallocatechin gallate (EGCG), nicotinamide riboside (NR), tricaprilin, vitamin E (α-tocopherol), cannabinoids, and NIC5-15 (D-pinitol). Trials were identified through ClinicalTrials.gov (search date: December 2024) and supplemented by PubMed searches for published results. Data were extracted on trial phase, design, cognitive/functional endpoints, biomarker outcomes, and development status. Findings are synthesized qualitatively; no formal meta-analysis or risk of bias assessment was conducted. Results: None of the nine bioactives demonstrated consistent cognitive efficacy in AD. Phase III trials of DHA, curcumin, and tricaprilin did not meet primary cognitive endpoints. Resveratrol reduced CSF Aβ40 without cognitive benefit. Cannabinoids improved behavioral symptoms but showed no measurable cognitive effects. High-dose vitamin E slowed functional decline, while cognition remained unchanged. In contrast, trials in preclinical or at-risk populations reported preliminary cognitive signals for EGCG and biomarker engagement for NR, suggesting potential for early intervention. Conclusions: Current clinical evidence does not support high-dose DBs supplementation as an effective treatment for AD. Predominantly negative late-phase findings highlight limitations, with potential contributors including limited bioavailability, late intervention, insufficient target engagement, and biological heterogeneity. Future research may benefit from early biomarker-defined populations, optimized formulations, multi-nutrient or dietary approaches, and precision nutrition strategies considering genetic risk and baseline nutrient status. DBs may be better positioned for prevention or early-stage intervention rather than late-stage therapy.

Nicotinamide adenine dinucleotide (NAD) augmentation therapy (NAD-AT) is increasingly explored in clinical trials across multiple indications, especially neurological diseases, yet its human pharmacokinetic profile remains incompletely defined. We report findings from a phase I pharmacokinetic trial assessing systemic and cerebral responses to oral NAD precursors in healthy individuals (n = 6) and persons with Parkinson's disease (n = 6) receiving 1,200 mg/day nicotinamide riboside or nicotinamide mononucleotide. Blood NAD increased slowly, plateauing after approximately two weeks of treatment, and declined with similarly slow kinetics following treatment discontinuation. Cerebral NAD levels increased measurably after four weeks of treatment. NAD-related metabolites showed faster increase and washout dynamics compared to NAD itself. Collectively, these data suggest that effective NAD-AT requires sustained oral administration over at least 2-4 weeks and that once-daily dosing is sufficient to maintain stable NAD levels. NAD responses exhibited considerable interindividual variability, but were not influenced by disease status or sex, indicating broad applicability. © 2026 The Author(s).