{
  "title": "NMN oral supplements: human evidence review",
  "scope": "Selected human research on swallowed oral NMN. Ingredient evidence, not finished-product trials.",
  "studies": [
    {
      "title": "Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women.",
      "doi": "10.1126/science.abe9985",
      "pmid": "33888596",
      "url": "https://pubmed.ncbi.nlm.nih.gov/33888596/",
      "short": "Muscle insulin sensitivity in prediabetes",
      "dose": "250 mg/day",
      "formulation": "Oral NMN, not a liposomal formula",
      "duration": "10 weeks",
      "population": "25 postmenopausal women with overweight or obesity and prediabetes",
      "result": "Insulin-stimulated glucose disposal increased after NMN but not placebo. Muscle insulin-signaling proteins also responded. The clamp test measures glucose handling under controlled insulin exposure, not everyday blood sugar control.",
      "null": "The result does not establish diabetes prevention, weight loss or broad metabolic improvement. Routine glucose and lipid results across trials were not significantly improved in the pooled review [5].",
      "limitations": "Small, narrowly defined population and short follow-up. Results in women with prediabetes cannot be assumed in younger adults, men or people without insulin resistance. The primary abstract verifies the muscle finding; sample size and dose are cross-checked in the review table.",
      "category": "metabolic",
      "citation": "Yoshino et al. · Science · 2021",
      "number": 1,
      "id": "study-33888596",
      "design": "Randomized double-blind placebo-controlled trial"
    },
    {
      "title": "Chronic nicotinamide mononucleotide supplementation elevates blood nicotinamide adenine dinucleotide levels and alters muscle function in healthy older men.",
      "doi": "10.1038/s41514-022-00084-z",
      "pmid": "35927255",
      "url": "https://pubmed.ncbi.nlm.nih.gov/35927255/",
      "short": "Blood NAD and physical function in older men",
      "dose": "250 mg/day",
      "formulation": "Conventional oral NMN",
      "duration": "6 and 12 weeks",
      "population": "42 healthy men aged 65 or older randomized; only 20 had valid week-12 data",
      "result": "Whole-blood NAD+ and related metabolites increased. Gait speed and left-hand grip had nominally significant improvements, meaning they were exploratory signals that need confirmation.",
      "null": "Body composition did not significantly change. The paper did not find a significant overall effect on right-hand grip. These are not findings of increased muscle mass or prevention of age-related disability.",
      "limitations": "At week 6, a supplier error gave 22 participants the opposite supplement. Their week-12 data were excluded, leaving 10 per group. Multiple functional tests and the reduced sample make the positive results less secure.",
      "category": "function",
      "citation": "Igarashi et al. · npj Aging · 2022",
      "number": 2,
      "id": "study-35927255",
      "design": "Randomized double-blind placebo-controlled parallel trial"
    },
    {
      "title": "The efficacy and safety of β-nicotinamide mononucleotide (NMN) supplementation in healthy middle-aged adults: a randomized, multicenter, double-blind, placebo-controlled, parallel-group, dose-dependent clinical trial.",
      "doi": "10.1007/s11357-022-00705-1",
      "pmid": "36482258",
      "url": "https://pubmed.ncbi.nlm.nih.gov/36482258/",
      "short": "Dose-ranging trial in middle-aged adults",
      "dose": "300, 600 or 900 mg/day",
      "formulation": "AbinoNutra NMN powder in 150 mg capsules; swallowed with water",
      "duration": "60 days",
      "population": "80 healthy adults aged 40 to 65; 20 in each of three NMN arms and placebo",
      "result": "Serum total NAD (NAD+ plus NADH) increased versus placebo at days 30 and 60 in all NMN groups (p ≤ 0.001). Six-minute walking-distance increases favored NMN at both visits (p < 0.01). SF-36 self-reported health scores also favored NMN at day 60.",
      "null": "HOMA-IR did not differ significantly from placebo at day 60. A calculator-derived biological-age value stayed unchanged with NMN while the placebo value increased. That is not evidence of reversed aging.",
      "limitations": "Only 20 people per arm, 60 days of follow-up, manufacturer co-sponsorship and several secondary endpoints. The walking test used a modified treadmill protocol. The serum assay is not a measurement of NAD+ inside muscle or other organs. No universal best dose was established.",
      "category": "biomarker",
      "citation": "Yi et al. · GeroScience · 2023 (online 2022)",
      "number": 3,
      "id": "study-36482258",
      "design": "Multicenter randomized double-blind placebo-controlled dose-ranging trial"
    },
    {
      "title": "Nicotinamide mononucleotide supplementation enhances aerobic capacity in amateur runners: a randomized, double-blind study.",
      "doi": "10.1186/s12970-021-00442-4",
      "pmid": "34238308",
      "url": "https://pubmed.ncbi.nlm.nih.gov/34238308/",
      "short": "Exercise thresholds in recreational runners",
      "dose": "300, 600 or 1,200 mg/day",
      "formulation": "Oral NMN powder in two daily doses, alongside exercise training",
      "duration": "6 weeks",
      "population": "48 recreational runners: 40 men and 8 women; 12 participants per arm",
      "result": "At 600 and 1,200 mg/day, selected oxygen-uptake and power measures at ventilatory thresholds improved more than control. Everyone followed training sessions of 40 to 60 minutes, five to six times per week.",
      "null": "VO2max, oxygen pulse and peak power did not show significant between-group differences. A higher ventilatory threshold is not the same as a higher maximum aerobic capacity or a faster race time.",
      "limitations": "Small, mostly male sample from one running team, short duration and an exercise co-intervention. Testing was performed on a cycle ergometer. Results cannot be attributed to supplementation without training or generalized to sedentary adults.",
      "category": "function",
      "citation": "Liao et al. · Journal of the International Society of Sports Nutrition · 2021",
      "number": 4,
      "id": "study-34238308",
      "design": "Randomized double-blind placebo-controlled four-arm trial with exercise"
    },
    {
      "title": "Effects of Nicotinamide Mononucleotide on Glucose and Lipid Metabolism in Adults: A Systematic Review and Meta-analysis of Randomised Controlled Trials.",
      "doi": "10.1007/s11892-024-01557-z",
      "pmid": "39531138",
      "url": "https://pubmed.ncbi.nlm.nih.gov/39531138/",
      "short": "Pooled glucose and lipid results",
      "dose": "250 to 2,000 mg/day across included trials",
      "formulation": "Oral NMN; formulations varied across trials",
      "duration": "14 days to 12 weeks",
      "population": "8 randomized trials reporting 342 participants in total, mainly relatively healthy middle-aged or older adults; 49% female",
      "result": "The review found no statistically significant pooled benefit for fasting glucose, fasting insulin, HbA1c, HOMA-IR or lipid profile. Five of the eight trials reported a rise in blood NAD-related measurements, showing that a biomarker response can coexist with null metabolic outcomes.",
      "null": "The HOMA-IR analysis was close to, but did not meet, the conventional significance threshold (p = 0.06). That is not a confirmed benefit. The review does not rule out every possible effect in every population.",
      "limitations": "Search through May 31, 2023; published in 2024. Small, short studies, mostly participants with normal baseline glucose and lipids. Not every outcome used all eight trials: some pooled estimates drew on only two or three. One trial with graph-only data could not be included in the numerical pooling. Publication bias could not be assessed reliably.",
      "category": "review",
      "citation": "Chen et al. · Current Diabetes Reports · 2024",
      "number": 5,
      "id": "study-39531138",
      "design": "Systematic review and random-effects meta-analysis of 8 RCTs"
    }
  ]
}