NAD+ dosage ranges studied in peer-reviewed clinical trials — oral, IV, and injectable
A consolidated reference from the published RCT record. Not a dosing recommendation — a literature summary.
Oral NMN: Dose Ranges in Human Trials
Oral NMN is the most extensively studied NAD+ precursor in humans as of 2026. The dose range across completed trials is 100–1200 mg/day.
Single-dose safety. Irie et al. (2020, Endocrine Journal) administered single oral doses of 100, 250, or 500 mg NMN to healthy Japanese men. All doses were safe and well-tolerated; dose-dependent increases in nicotinamide metabolites were confirmed; no adverse effects on vitals, hematology, or biochemistry.[3]
12-week sustained supplementation. Okabe et al. (2022, Frontiers in Nutrition) showed 250 mg/day for 12 weeks significantly elevated whole-blood NAD+ at weeks 4, 8, and 12; NAD+ returned to baseline within 4 weeks of stopping; no safety signals.[4]
Metabolic endpoints. Yoshino et al. (2021, Science) used 250 mg/day for 10 weeks in postmenopausal women with prediabetes; skeletal muscle insulin sensitivity improved significantly vs placebo; no liver metabolic benefit.[5]
Dose-response. Yi et al. (2022, GeroScience) tested 300, 600, and 900 mg/day for 60 days in middle-aged adults; blood NAD+ elevated significantly at days 30 and 60 across all groups (p≤0.001); 600 mg/day identified as optimal for the combination of NAD+ elevation and walking distance improvement.[6]
Physical function in older men. Igarashi et al. (2022, NPJ Aging) — 250 mg/day for 12 weeks; gait speed (p=0.033) and grip strength (p=0.019) significantly improved in completers (n=20).[7]
Exercise combination. Liao et al. (2021, JISSN) — 300, 600, or 1200 mg/day for 6 weeks with exercise training; VO₂max improved dose-dependently at 600 and 1200 mg/day groups vs placebo.[17]
Oral NR: Dose Ranges in Human Trials
NR's trial record spans 250–3000 mg/day. Unlike niacin, NR does not cause vasodilatory flushing at any studied dose.
Dose-response. Conze et al. (2019, Scientific Reports) — 100, 300, or 1000 mg/day NR for 8 weeks in healthy overweight adults; blood NAD+ elevated 22%, 51%, and 142% respectively vs placebo; no LDL elevation, no methyl-donor depletion, no flushing.[8]
MCI population. Orr et al. (2024, GeroScience) — 1 g/day NR for 10 weeks in older adults with MCI; 2.6-fold blood NAD+ elevation confirmed; cognitive performance unchanged on MCA and related tests.[20]
High-dose safety ceiling. Berven et al. (2023, Nature Communications, NR-SAFE trial) — 3000 mg/day (1500 mg twice daily) for 30 days in Parkinson disease patients; primary endpoint (safety) met — no moderate or severe adverse events; blood and urine NAD+ metabolome substantially elevated; no significant improvement in MDS-UPDRS PD severity score at this dose and duration.[18]
FDA RULING // 2023
NR is currently a legal dietary supplement in the US. NMN was classified as a drug ingredient by FDA in January 2023, creating regulatory ambiguity for retail NMN sales. Licensed practitioners may use compounded NAD+ or NMN in clinical settings.
Intravenous NAD+ Dose Ranges in Published Research
IV NAD+ data is limited to pilot studies and case series as of 2026.
PK pilot. Grant et al. (2019, Frontiers in Aging Neuroscience) — 750 mg NAD+ over 6 hours (~2 mg/min rate) in healthy males; plasma NAD+ and metabolites elevated throughout and detected in urine; no adverse events at this infusion rate.[9]
Real-world tolerability comparison. Reyna et al. (2026, Frontiers in Aging) — 500 mg IV NAD+ vs 500 mg IV NR over 4 consecutive days; IV NAD+ required mean 97-minute infusion for moderate-to-severe symptoms; IV NR required 37 minutes with only mild tingling.[10]
Addiction protocols. 500–1000 mg/day IV NAD+ in normal saline for 4 days, then maintenance dosing (O'Hollaren 1961, reviewed Braidy et al. 2020).[12] Modern formulation: 750 mg over an appropriate infusion period.
Clinical tolerance rule. Infusion rates exceeding 2 mg/min are associated with increased frequency and severity of nausea, chest pressure, and heart rate elevation.[9][10] Rate control is the primary management tool for infusion reactions.
NAD+ Half-Life and Pharmacokinetics
Orally administered NMN is rapidly absorbed and metabolized in mouse models: plasma NMN peaks within 15 minutes of ingestion and converts to NAD+ in peripheral tissues within 60 minutes. Blood NAD+ elevation from single oral NMN or NR doses returns to baseline within 24 hours; daily dosing maintains elevated levels as confirmed across multiple 8–12-week human trials.[4][8]
For IV NAD+, the Grant et al. 2019 pilot study established that plasma NAD+ is elevated throughout a 6-hour infusion at 2 mg/min (750 mg total) and that metabolites persist in urine for hours post-infusion.[9] Formal plasma half-life data from IV administration in humans has not been published as of 2026.
For SC/IM injection, bioavailability and half-life data are under active investigation in registered trials; no published PK characterization is available as of 2026.