One trial had people walking further; nothing since has repeated it
80 healthy middle-aged adults took 300, 600 or 900 mg a day for 60 days and beat placebo on six-minute walking distance. No later pooled analysis has reproduced it.
What the study found
The walking gain in NMN's largest dose trial has not replicated
Eighty healthy middle-aged adults took 300, 600 or 900 mg of NMN a day for sixty days. Blood NAD rose at every dose, and six-minute walking distance beat placebo in all three arms. Insulin resistance did not budge, and no later pooled analysis has reproduced the walking result.
The caveat · Counted only those who stuck with it
Twenty people per arm across four arms, analysed per protocol rather than by intention to treat, in healthy adults over sixty days. The first author works for an NMN company and two co-authors for NMN raw-material producers. The trial's biological-age outcome comes from a free online calculator rather than a validated clinical instrument.
What we don't know
Whether NMN helps people walk further is unsettled. The one trial that found it was run by companies selling NMN and tested healthy middle-aged adults; a later pooling in older adults did not repeat it.