Longevity & Aging · Supplements
NAD+ precursors (NMN, NR) increases cellular NAD+
In plain terms: Do NMN or NR supplements raise NAD+, a key cell-fuel molecule?
Part of: 🧪 nad+ precursors (nmn, nr)
Yes — they reliably raise blood levels in trials, but that is not a proven health benefit.
📅 Last reviewed: 2026-07-14 ⓘ
Evidence ladder
How far up the ladder this claim has climbed. A high consensus on a low rung means "consistent so far," not "proven in people."
Top evidence so far: All trials, pooled (Meta-analysis)
How the studies fall
What the evidence shows
NMN/NR supplementation reliably raises blood NAD+ in human RCTs - the best-supported NAD claim (multiple independent groups + meta-analysis).
The evidence (19)
| Source | Grade | Stance | Quality | Finding |
|---|---|---|---|---|
| Ahmadi 2023 · JCI Insight | RCT | mixed | low | Crossover RCT in CKD: NR (1000 mg/d) altered NAD-dependent TCA/metabolome but did not improve VO2/work; NAD-pathway engagement without functional gain. |
| Yi 2023 · GeroScience | RCT | supports | moderate | [FT-verified] FT RCT n=80 dose-resp blood NAD up p<0.001; CAVEAT industry co-sponsored, colorimetric assay |
| Conze 2019 · Scientific Reports | RCT | supports | high | 8-wk RCT in overweight adults: NR (NIAGEN) dose-dependently increased whole-blood NAD+ ~22-51% vs placebo; well tolerated. |
| Remie 2020 · Am J Clin Nutr | RCT | mixed | moderate | 6-wk NR in obese humans raised muscle NAD+ metabolites (MeNam) and altered body composition, but several metabolic endpoints null. |
| Berven H 2026 · (2026 phase-I PK trial) | RCT | supports | moderate | Phase-I PK RCT (n=12: 6 healthy + 6 Parkinson) 1200 mg/day oral NR or NMN: blood NAD+ increased, plateauing ~2 weeks; cerebral NAD+ measurably rose by 4 weeks — direct human evidence the precursors raise NAD+ (large interindividual variation). |
| Trammell 2016 · Nature Communications | RCT | supports | high | First-in-human: single oral NR dose dose-dependently raised blood NAD+ metabolome up to ~2.7x; landmark oral bioavailability proof. |
| Pencina 2023 · J Gerontol A | RCT | supports | moderate | MIB-626 microcrystalline NMN significantly increased circulating NAD and its metabolome ↩ SUPERSEDED — pooled in the review above, counted once |
| Prokopidis 2025 · J Cachexia Sarcopenia Muscle | meta-analysis | tested-null | moderate | SR/MA of NMN & NR RCTs: precursors raise NAD+ but no consistent benefit on muscle mass/function; honest \"raises NAD+, downstream effects unproven.\ |
| Brakedal 2022 · Cell Metabolism | RCT | supports | high | NADPARK: 30-day NR significantly augmented cerebral and blood NAD+ in Parkinson's patients (variable responders); independent group, brain NAD+. |
| Kuerec 2024 · Mech Ageing Dev | RCT | supports | moderate | Post-hoc of NMN RCT: dose-dependent rise in blood NAD+ across 300-900 mg/d in healthy adults; confirms NMN raises blood NAD+. |
| Berven 2023 · Nat Commun | RCT | supports | high | NR-SAFE: high-dose NR (3000 mg/d) safely raised whole-blood NAD+ up to ~5-fold in Parkinson's; dose-response confirmation. |
| Martens 2018 · Nat Commun | RCT | supports | moderate | [FT-verified] FT crossover n=24 NAD+ +60% but p=0.048 one-sided unadj; NAAD more robust; NIAGEN/ChromaDex. Holds |
| Elhassan 2019 · Cell Rep | RCT | supports | high | 21-day NR in aged men raised skeletal-muscle and blood NAD+ metabolome and lowered inflammatory cytokines; tissue-level NAD+ augmentation. |
| Shoji 2025 · Aging Cell | RCT | supports | moderate | Crossover RCT: NR raised NAD+ and gave benefits in Werner-syndrome patients; independent confirmation of NR->NAD+ in a clinical population. |
| Dollerup 2018 · Am J Clin Nutrition | RCT | mixed | moderate | 12-wk NR RCT in obese men: NAD-metabolome shifts but blood NAD+ rise not statistically significant; no insulin-sensitivity benefit (raises-NAD signal weaker here). |
| Christen 2026 · Nat Metab | RCT | supports | moderate | Head-to-head: three NAD precursors differentially raise the NAD+ metabolome in humans; NMN/NR raise NAD+ but compartment/route effects differ. |
| Chen 2024 · Current Diabetes Reports | meta-analysis | supports | moderate | SR/MA of NMN RCTs: significant elevation of blood NAD+ with NMN, but no robust glucose/lipid benefit; corroborates the NAD+-raising endpoint specifically. |
| Zhang 2025 · Crit Rev Food Sci Nutr | meta-analysis | supports | moderate | MA (12 RCTs, n=513): NMN significantly elevates blood NAD, but most clinical metabolic outcomes not improved |
| Yoshino 2021 · Science | RCT | supports | high | NMN RCT in prediabetic women raised muscle NAD+ metabolome and improved muscle insulin sensitivity; independent NMN evidence. ↩ SUPERSEDED — pooled in the review above, counted once |
Disagree, or know a study we missed?
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Educational only, not medical advice. Grades and scores reflect published evidence weighted by study design and quality; see the methodology.