NAD+ Decline With Age: What the Research Has Established (and What It Hasn’t)

NAD+ decline with age is one of the more consistently replicated findings in aging biology research — but there’s an important distinction between what’s well established (the decline itself) and what’s still being actively researched (what that decline means for specific health outcomes).

Informational only — not medical advice.*

What’s Well Established

Multiple independent studies, across different tissue types and measurement methods, have documented that NAD+ levels measured in blood and tissue samples tend to be lower in older subjects compared to younger ones. This pattern has been observed consistently enough that it’s considered one of the more reliable biomarker trends in aging research.

Why NAD+ Matters at the Cellular Level

NAD+ is a coenzyme involved in hundreds of metabolic reactions, most notably as an electron carrier in mitochondrial energy production. It’s also a required substrate for sirtuins and PARP enzymes, both involved in DNA repair and cellular stress response pathways. This central role is why its age-related decline has drawn significant research interest.

What’s Still Being Researched

• Whether raising NAD+ levels via precursors like NMN or NR translates to measurable functional or health outcomes in humans — most robust data so far comes from animal models.
• The precise mechanisms driving the decline itself (increased consumption by CD38 and other NAD+-consuming enzymes is one studied hypothesis, among others).
• Optimal intervention timing, dosing, and which populations might see the most benefit from supplementation, if any.

Where This Leaves Things

The decline is well documented; what to do about it, and whether doing anything changes meaningful outcomes, is where the research is still developing. Sierra Life Sciences manufactures NMN Cellular Performance for those following this research area. Talk to your healthcare provider about what’s appropriate for you.

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.