Evidence verdict: NAD+ is central to energy metabolism, redox chemistry and signaling, and age-related NAD dysregulation is biologically plausible. But human evidence for a universal age-related decline across tissues is much less complete than common marketing claims imply. NR and NMN reliably raise NAD-related biomarkers; clinical healthspan benefits…
Evidence verdict: AMPK is a central cellular energy sensor that coordinates catabolic metabolism, mitochondrial adaptation and autophagy while intersecting with mTOR and sirtuin signaling. It is strongly implicated in longevity biology, but direct evidence that pharmacologically activating AMPK extends human lifespan is absent.
Evidence verdict: mTOR—especially mTORC1—is one of the most conserved and experimentally supported nutrient-sensing pathways in aging. Inhibiting mTOR extends lifespan across multiple model organisms, but that does not establish that rapamycin extends lifespan in healthy humans.