NMN left grip, gait speed and chair-stand time unchanged
Pooled across trials in adults over 60, NMN shifted grip strength by about half a kilogram and gait speed by 0.01 m/s, none of it separable from placebo.
What the study found
Pooled trials show NMN doing nothing for ageing muscle
The sarcopenia rationale predicts stronger, faster older bodies. Pooled across randomised trials in adults over 60, NMN shifted grip strength by about half a kilogram, gait speed by 0.01 m/s and chair-stand time by a fifth of a second, none of it separable from placebo.
The caveat · Two to five trials per outcome
Between two and five trials per outcome, so a real effect could still be hiding in an evidence base this thin. What argues against that is how closely the trials agreed with each other: they scattered almost not at all around the null. The nicotinamide riboside results could not be pooled and ran in both directions, longer six-minute walks in peripheral artery disease against worse physical performance scores in mild cognitive impairment.