Supplement
Nicotinamide riboside (NR)
Nicotinamide riboside is the other widely sold NAD+ precursor. It has been studied in humans for longer than NMN, including in specific patient groups, which makes its evidence base somewhat more informative — though it points at the same unresolved question of whether raising NAD+ changes health outcomes.
Quick verdict
Human trials support that NR raises NAD+ and is tolerated. Trials in specific conditions have produced mixed results, and no human lifespan evidence exists.
The assessment
Claim by claim
Each claim is graded on its own evidence. A grade for one claim says nothing about the others.
| Claim | What was measured | Evidence |
|---|---|---|
| Improves outcomes in specific diagnosed conditions | Disease outcome | Early |
| Extends human lifespan | Lifespan | Insufficient |
Improves outcomes in specific diagnosed conditions
Early human evidenceOutcome measured: Disease outcome — A diagnosed condition or clinical event was measured.
Randomised trials have tested NR in defined patient groups, including a crossover trial in Werner syndrome and trials in cognitive impairment and hypertension.
Why this grade — the appraisal in full
One or a small number of small, short or preliminary human studies. Directionally interesting, not yet dependable.
- Strongest study design. Randomised controlled trial.
- Human research volume. 3 human studies, 0 participants in total.
- What was measured. 2 human studies measured a clinical or functional outcome rather than a laboratory marker alone.
- Replication. The supporting result has not been independently replicated in humans.
Limitations. These are small trials in specific conditions. Results in a rare genetic syndrome or a diagnosed patient group do not generalise to healthy adults taking a supplement.
| Study | Design | Population | Finding |
|---|---|---|---|
| [1]Nicotinamide Riboside Supplementation Benefits in Patients With Werner Syndrome:…Aging cell · 2025 · PMID 40459998 | Randomised controlled trialHuman | Size not recordedParticipants with a diagnosed condition | Supports the claimDouble-blind randomised crossover trial in patients with Werner syndrome. |
| [2]A phase-II randomized controlled pilot study of nicotinamide riboside supplement…Alzheimer's & dementia : the journal of the Alzheimer's Association · 2026 · PMID 42478598 | Randomised controlled trialHuman | Size not recordedParticipants with a diagnosed condition | Direction not yet appraisedPhase II randomised controlled pilot in older adults with amnestic cognitive impairment. |
| [3]Nicotinamide riboside combined with exercise to treat hypertension in middle-age…GeroScience · 2025 · PMID 40770531 | Randomised controlled trialHuman | Size not recordedParticipants with a diagnosed condition | Direction not yet appraisedPilot randomised trial of NR combined with exercise for hypertension. |
Extends human lifespan
Insufficient evidenceOutcome measured: Lifespan — Death from any cause was measured.
No human study has measured whether NR affects lifespan.
Why this grade — the appraisal in full
Too little credible research exists to judge the claim either way.
- Available research. No usable studies are linked to this claim.
Limitations. As with all NAD+ precursors, the lifespan case rests on animal work.
Human evidence
3 studies in people.
- [1]Randomised controlled trial
- [2]Randomised controlled trial
- [3]Randomised controlled trial
Animal and laboratory evidence
Shown separately, and never used to support a human claim.
No preclinical study is currently linked on this page.
Before anything else
Safety and interactions
Reported as well tolerated across published trials at commonly used doses. As with NMN, multi-year safety data in healthy adults is limited.
The ledger
Grade history
No grade on this page has changed since tracking began. When one moves — a new trial, a retraction, a corrected appraisal — the change is detected automatically and recorded on the public ledger.
Falsifiability
What would change our view
Consistent, independently replicated functional benefits in adequately powered trials — particularly in healthy older adults rather than disease-specific populations.
Check everything
Sources
Every citation links to its PubMed record. Bibliographic details are retrieved from PubMed, not written by us.
- [1]Nicotinamide Riboside Supplementation Benefits in Patients With Werner Syndrome: A Double-Blind Randomized Crossover Placebo-Controlled Trial Shoji M et al.. Aging cell. 2025. PMID 40459998 · doi:10.1111/acel.70093
- [2]A phase-II randomized controlled pilot study of nicotinamide riboside supplementation in older adults with amnestic mild cognitive impairment Martens CR et al.. Alzheimer's & dementia : the journal of the Alzheimer's Association. 2026. PMID 42478598 · doi:10.1002/alz.71605
- [3]Nicotinamide riboside combined with exercise to treat hypertension in middle-aged and older adults: a pilot randomized clinical trial Lin Y et al.. GeroScience. 2025. PMID 40770531 · doi:10.1007/s11357-025-01815-2