NMN
Nicotinamide Mononucleotide
A direct NAD+ precursor studied for metabolic and physical-function benefits in aging, with early human trials and a contested regulatory status in the US.
Overview
NMN is a precursor the body converts into NAD+. Animal studies reported improvements in insulin sensitivity, endurance, and age-related decline, and early human trials have examined insulin sensitivity, muscle function, and biomarkers with modest results. In 2022 the FDA concluded NMN is excluded from the dietary supplement definition because it had been authorized for investigation as a drug, leaving its US supplement status contested.
Mechanism of action
Converts to NAD+ through the salvage pathway, aiming to restore NAD+ levels that decline with age.
Key studies & citations
- Human2021
Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women
10-week RCT in overweight or obese postmenopausal women with prediabetes: 250 mg/day NMN increased muscle insulin sensitivity and insulin signaling versus placebo; other metabolic outcomes did not change.
Science - Human2023
The efficacy and safety of beta-nicotinamide mononucleotide (NMN) supplementation in healthy middle-aged adults: a randomized, multicenter, double-blind, placebo-controlled, dose-dependent clinical trial
60-day RCT in 80 adults: 300 to 900 mg/day raised blood NAD and modestly improved six-minute walk distance; well tolerated; HOMA-IR unchanged.
GeroScience - Animal2016
Long-term administration of nicotinamide mononucleotide mitigates age-associated physiological decline in mice
12 months of oral NMN in ageing mice improved insulin sensitivity, energy metabolism, physical activity and eye function without obvious toxicity.
Cell Metabolism
Frequently asked questions
Is NMN better than NAD+ directly?
NMN is a precursor that the body converts to NAD+ and is easier to take orally, but whether either meaningfully slows aging in humans is not established.