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

Yi L, et al. · GeroScience

Blood NAD+ rose in all three NMN arms against both placebo and baseline (all P<=0.001), and the rise was larger at 600 mg than at 300 — but not larger again at 900, so the dose-response levels off, and the authors put the ceiling at 600 mg/day. Six-minute walking distance was longer than placebo in all three arms (all P<0.01), by roughly 100 to 150 metres, and no safety concerns emerged up to 900 mg/day; no joint outcomes were assessed.

Population

Healthy adults aged 40-65, mean age 49, 59% women, 20 per arm, 60 days

Intervention

NMN 300, 600 or 900 mg/day orally for 60 days

Comparator

Placebo

Limitations

Co-sponsored by the two companies that make and sell the product tested (Aba Chemicals and Abinopharm), three of whose employees are authors. Analysed per protocol. The walking gains are very large for two months in healthy adults — around 45% over baseline, several times what is usually called a meaningful change — and were measured on a treadmill standing in for a walking course, which is reason to treat that endpoint cautiously rather than as the trial's strength. Sixty days; no joint or cartilage measures.