Longevity Evidence Lab Human evidence, uncertainty intact
Research interpretation, not diagnosis or personal treatment advice. Urgent symptoms belong with a clinician, not a browser tab.
Home / Evidence / Nicotinamide riboside (NR)
NAD+ precursor

Nicotinamide riboside (NR)

Biologically active and well studied for NAD elevation; clinical outcome evidence is thin.

The 30-second verdict NR reliably alters NAD metabolism in many human studies, but biomarker movement has not translated into a consistent package of functional or disease benefits. It should be viewed as an active NAD precursor under clinical investigation rather than established longevity therapy.

Evidence matrix

These scores describe different evidence domains. A strong mechanism cannot compensate for missing human outcomes, and a useful clinical effect need not imply slower biological ageing.

Human clinical outcomes Preliminary
Human biomarkers Strong
Animal lifespan Limited
Mechanistic plausibility Moderate
Safety certainty Limited
Direct longevity relevance Preliminary

What has been shown in humans?

Trials have investigated vascular, metabolic, muscle, inflammatory and neurological outcomes with mixed results. Study populations, doses and endpoints vary substantially.

What remains uncertain?

The people most likely to benefit, meaningful clinical endpoints, multi-year safety and comparative value against inexpensive niacin-family alternatives remain uncertain.

Doses used in research

Descriptive, not prescriptive Studies use a broad range, often several hundred milligrams to around one gram daily. Study doses do not establish an optimal personal dose.

Safety and interpretation

  • Short-term tolerability is generally acceptable in published trials.
  • Long-duration outcome and safety data remain limited.
  • Combining NR with NMN mostly duplicates the same intended pathway without evidence that the combination is superior.

Primary sources and evidence reviews

Editorial note

This dossier was last reviewed on 13 July 2026. Ratings can change when larger trials, adverse-event data or better systematic reviews appear. Corrections should alter the page rather than being buried in a social-media thread.