NAD+, NMN and NR: Promising Biology, Thin Human Evidence
NAD+ genuinely declines with age and genuinely matters. Whether swallowing a precursor changes anything you would notice is a separate and much less settled question.
NAD+ & NMN
NAD+ falls with age and is required by every energy-producing reaction in the cell, which makes restoring it an attractive target. Whether oral precursors raise tissue NAD+ enough to matter is still an open question, and the human outcome data is thin. These pages cover the mechanism honestly and mark the gap between it and proof.
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