Nicotinamide Mononucleotide Is Safely Metabolized and Significantly Reduces Blood Triglyceride Levels in Healthy Individuals
Shintarou Kimura et al. · Cureus · 2022
Evidence type: Early human interventionInterpretive weight: LimitedResearch area: Intravenous NMN metabolism and short-term tolerability
DesignOpen-label, single-arm exploratory intervention with serial measurements over five hours after one dose.
PopulationTen healthy Japanese adults aged 20–70 years (five men and five women).
Sample10 participants
InterventionA single 300 mg intravenous NMN infusion in 100 mL saline at 5 mL/min after a 12-hour fast; no placebo or untreated comparator.
EndpointsVital signs, ECG, chest radiography, urinalysis, and adverse events; Liver, pancreatic, cardiac, renal, hematologic, glucose, protein, and lipid measures; Whole-blood NAD+ and NADH; SIRT1 protein and NAMPT, NANOG, and p16 gene expression
What the publication reported
Ten healthy adults received one intravenous infusion of 300 mg NMN and were monitored for five hours. The investigators reported no acute safety abnormalities in the measured clinical tests. Blood NAD+ rose and triglycerides fell during the observation window, while many other laboratory measures did not change. Because the study was very small, uncontrolled, intravenous, and brief, it can only provide preliminary information about short-term metabolism and tolerability.
Key findings
No clinically apparent acute abnormalities were reported in vital signs, ECG, chest radiography, urinalysis, organ-function markers, or blood counts during the five-hour window. Whole-blood NAD+ increased after the infusion, whereas triglycerides decreased significantly from 0.5 to 5 hours. Total, LDL, and HDL cholesterol, glucose, protein measures, and several organ markers did not change significantly. Nuclear SIRT1 showed a nonsignificant upward trend; cytosolic SIRT1 and NANOG were unchanged. NAMPT mRNA increased and p16 mRNA decreased.
What it cannot establish
The study enrolled only 10 participants and had no placebo or untreated control. It assessed a single intravenous dose for five hours, so fasting, regression to the mean, or normal short-term variation could contribute to observed changes. The route does not represent oral supplementation. Multiple exploratory endpoints were assessed, and the study cannot establish durability, long-term safety, clinical benefit, or effects in people with disease.
HealthspanX claim boundary: These findings concern a single 300 mg intravenous NMN infusion under fasting conditions. They do not establish equivalence to oral NMN or HealthspanX Ultra Pure NMN, long-term safety, sustained triglyceride lowering, disease prevention, or disease treatment.
