Supplement analysis backed by scientific evidence · PT

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Limited evidenceLongevity & antioxidants

NMN (Nicotinamide Mononucleotide)

NMN reliably raises blood NAD+ levels, but raising a biomarker is not the same as producing a benefit — meta-analyses of the human trials find no meaningful effect on metabolism, muscle or blood pressure. It is also no longer legally sellable as a dietary supplement in the US.

What the science says

  • Raising NAD+ levels Moderate evidence

    Multiple placebo-controlled trials show oral NMN at 250-1,250 mg/day increases whole-blood NAD+ by roughly 40-140% over 6-12 weeks in a dose-dependent way. This is the one consistently reproduced finding. Whether NMN is absorbed intact or first converted to nicotinamide riboside/nicotinamide in the gut remains contested.

  • Glucose and lipid metabolism Limited evidence

    A 2024 systematic review and meta-analysis of RCTs found NMN had no significant effect on fasting glucose, HbA1c, insulin, HOMA-IR, total cholesterol, LDL, HDL or triglycerides in adults. The often-cited 2021 Science trial in prediabetic postmenopausal women reported improved muscle insulin sensitivity by clamp, but this was a small (25-person) study with no change in any other metabolic endpoint, and it has not been replicated.

  • Muscle function and physical performance Limited evidence

    A 2025 systematic review and meta-analysis in Journal of Cachexia, Sarcopenia and Muscle pooled NMN and NR trials and found no significant effect on skeletal muscle mass or strength. Individual NMN trials reporting improved 6-minute walk distance or gait speed have been small, short and inconsistently blinded.

  • Anti-aging and longevity Limited evidence

    No human trial has measured aging, disease incidence or mortality with NMN. The enthusiasm derives from mouse studies in which NMN improved insulin sensitivity and mitochondrial function; mouse lifespan extension with NMN has not been robustly demonstrated in the way it has for, say, rapamycin.

Dosage & safety

Studied doseHuman trials have used 250-1,250 mg/day for 6-12 weeks, most commonly 250-500 mg/day taken in the morning. NAD+ elevation is dose-dependent up to about 900 mg/day. No dose has been shown to produce a clinical benefit, so there is no evidence-based recommendation.
SafetyWell tolerated in trials up to 1,250 mg/day for 12 weeks, with no consistent adverse-effect signal beyond mild nausea, flushing or GI upset. Long-term (>1 year) human safety data do not exist. Regulatory note: in 2022 the US FDA concluded NMN is excluded from the dietary supplement definition because it was authorized for investigation as a new drug, so NMN is not lawfully marketed as a supplement in the United States — Amazon and other major retailers have delisted it, and product identity/purity in the grey market is a real concern. Australia has classified NMN as a prescription-only substance at higher doses. Because NAD+ metabolism supports cell proliferation, and some tumours upregulate the NAMPT salvage pathway, people with an active cancer should not take it without oncologist input.

Scientific references

Where to buy

California Gold Nutrition, NMN, 175 mg, 60 Veggie Capsules

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