Supplement evidence

048 / 575Experimental longevity

Nicotinamide riboside (NR)

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The short answer

Human trials show increases in NAD-related metabolites; clinical effects are inconsistent.

Evidence and scope: Emerging evidence
This status does not grade the ingredient for every goal, outcome, or person.
Important limitation: Raising NAD markers has not demonstrated human rejuvenation or lifespan extension.
Before deciding: Short-term tolerability appears reasonable; long-term safety and value remain uncertain.

01 / PRACTICAL GUIDE

Dose, absorption, and combinations

These are indication-specific reference or studied ranges—not a personalized prescription. Start with the objective, then check the form, label, medicines, and health conditions.

Reference range by objective

Meeting usual needs300–1,000 mg/day in short human trials; no established health dose

Reference or studied range—not a personalized prescription. The product label or a clinician may specify a different dose.

Dose source ↗

More is not automatically better. A clinician or product label may specify a different amount.

Absorption / solubilityWater-soluble

Water-soluble or readily water-dispersible. This does not mean excess is always harmless.

How it is commonly taken

May be taken with or without food.

Do not combine casually

Long-term clinical benefit and safety are uncertain; review cancer treatment, pregnancy, and stacked NAD precursors.

Dose and use source ↗

Dose and use links lead to primary or official source material. Search links are discovery tools, not proof that every returned paper applies.

02 / EVIDENCE

What the research says

We keep supportive, mixed, negative, safety, and contextual findings together. The headline never replaces the underlying papers.

4research papers in this ledger

4unique primary studies represented

97unique participants represented

These are audited counts for this JIVANA collection, not search-result totals. Participants are counted once when multiple papers use the same cohort; review papers are not added again to participant totals.

Open the research timelineResearch timeline

Entries are ordered by publication year. A study period appears only when the source reports it.

2023

Does not support the tested claimPMID 37994989

A randomized placebo-controlled trial of nicotinamide riboside in older adults with mild cognitive impairment

Blood NAD⁺ rose 2.6-fold without more adverse events, but cognition and other neuropsychological measures did not improve. Raising the target biomarker did not establish cognitive benefit.

Published: 2023Duration: 10 weeksn=20 participants

Study design and methods

Design: Randomized placebo-controlled pilot trial
Population: 20 older adults with mild cognitive impairment
Intervention: Dose-escalated nicotinamide riboside to 1 g/day or placebo
Outcome: Safety, blood NAD⁺, cognition, cerebral blood flow, and physical performance

Open research record ↗

2020

Mixed or qualifiedPMID 32320006 · NCT02835664

Nicotinamide riboside supplementation alters body composition and skeletal muscle acetylcarnitine concentrations

NR increased muscle NAD-related and acetylcarnitine metabolites and made small body-composition changes, but did not improve insulin sensitivity, mitochondrial function, blood pressure, inflammation, liver or muscle fat, or cardiac function.

Published: 2020Duration: Two 6-week periodsn=13 participants

Study design and methods

Design: Randomized, double-blind, placebo-controlled crossover trial
Population: 13 overweight or obese adults
Intervention: Nicotinamide riboside 1,000 mg/day or placebo
Outcome: Muscle NAD-related metabolites, insulin sensitivity, mitochondrial function, body composition, blood pressure, inflammation, and cardiac measures

Open research record ↗

2018

Does not support the tested claimPMID 29992272 · NCT02303483

A randomized placebo-controlled clinical trial of nicotinamide riboside in obese men

NR was tolerated but did not improve insulin sensitivity, glucose metabolism, lipid mobilization, energy expenditure, liver fat, or body composition.

Published: 2018Duration: 12 weeksn=40 participants

Study design and methods

Design: Randomized, double-blind, placebo-controlled parallel trial
Population: 40 sedentary obese, insulin-resistant men aged 40–70
Intervention: Nicotinamide riboside 2,000 mg/day or placebo
Outcome: Clamp-measured insulin sensitivity, glucose and lipid metabolism, energy expenditure, liver fat, and body composition

Open research record ↗

2018

Mixed or qualifiedPMID 29599478

Chronic nicotinamide riboside supplementation is well-tolerated and elevates NAD+ in healthy middle-aged and older adults

NR increased NAD-related metabolites and was tolerated. Blood-pressure and arterial-stiffness findings were preliminary subgroup or exploratory signals, not confirmed clinical benefit.

Published: 2018Duration: Two 6-week periodsn=24 participants

Study design and methods

Design: Randomized, double-blind, placebo-controlled crossover trial
Population: 24 healthy middle-aged and older adults
Intervention: Nicotinamide riboside or placebo
Outcome: NAD metabolism, tolerability, blood pressure, and arterial function

Open research record ↗

Unscreened discovery appendix—not evidence46 candidate publicationsSearch run: Aug 21, 2026

Complete for the displayed PubMed query at the search timestamp—not for all databases or every possible synonym. Candidates can be irrelevant, duplicate the same study, or report negative findings. They are never summed as evidence or participants until screened.

03 / SOURCES

Start with the source material

Official evidence overviewPubMed human-evidence index Live PubMed discovery searchNational Library of Medicine

The live search is for discovery only. Search-result counts change and are not included in the audited totals above.

Recent PubMed discovery recordsDirect links to the first 12 records returned by the reproducible search. These are discovery candidates—not reviewed summaries or a count of supportive findings.

04 / EXPERT CONTEXT

Expert context—not evidence

Expert positions are dated context—not scientific evidence. They never raise the evidence status or become consensus by repetition.

No direct, source-verified endorsement is currently recorded. Research authorship or discussion alone is not treated as endorsement.