Research review
nicotinamide riboside (NR) benefits: what the research does and doesn't show
Nicotinamide riboside reliably raises blood NAD+ in human trials, but the larger, longer trials measuring actual physiological outcomes — insulin sensitivity, mitochondrial function, blood pressure, body composition — have mostly found no significant effect; a 2023 review of 25 human studies concluded the field has shown few clinically relevant benefits.
The evidence doesn't support nicotinamide riboside, at any studied dose, for slowing aging, treating a disease, or improving metabolic health in generally healthy people. What it does reliably do is raise blood NAD+ — and that biomarker change is where most of the trial evidence stops. When researchers have gone on to measure an actual physiological outcome, the larger and longer trials have mostly come back null.
What the evidence doesn't support
It doesn't support nicotinamide riboside (NR) as an anti-aging treatment, a way to extend human lifespan, a treatment for a diagnosed disease, or a reliable way to improve insulin sensitivity, body composition, or exercise capacity in a healthy adult. NAD+ has been reported to decline with age in animal models, but a 2019 human trial notes plainly that human data on that decline are sparse (PMID 31412242) — the "NAD+ declines with age, so raising it should help aging" argument is built mostly on preclinical work, not on human aging data. A 2023 review that assessed all 25 published human NR studies available at the time concluded that, collectively, oral NR supplementation has displayed few clinically relevant effects, and specifically warned that the literature has a tendency to exaggerate the importance and robustness of what's been reported (PMID 37478182). Individual trials in that review found no effect of chronic NR on mitochondrial volume or respiration, insulin sensitivity, body composition, cardiac function, lipolysis, peak exercise capacity, or substrate use at rest or during exercise.
What the trials found
The first published human trial, in 2016, established that NR raises blood NAD+ at all: a single dose in one person raised it as much as 2.7-fold, and in a follow-up group of 12 healthy adults, single doses of 100, 300 and 1,000 mg each produced a dose-dependent rise in the blood NAD+ metabolome (PMID 27721479). An 8-person, open-label pharmacokinetics study found a similar pattern with repeated dosing — NAD+ roughly doubled at steady state after doses escalating up to 1,000 mg twice daily, with no adverse events reported (PMID 29211728). A larger, placebo-controlled trial of 140 overweight adults confirmed the dose-dependent NAD+ rise over 8 weeks (22%, 51%, and 142% at 100, 300, and 1,000 mg/day) — but that trial's design measured pharmacokinetics and safety, not a clinical health outcome (PMID 31278280). All three trials measured the same thing: NAD+ goes up. None of them measured whether that made any difference to how a person felt or functioned.
The trials that did look further mostly found nothing further. A 12-week trial of 40 obese, insulin-resistant men given 2,000 mg of NR a day found no improvement in insulin sensitivity, endogenous glucose production, glucose disposal, resting energy expenditure, lipolysis, or body composition compared with placebo — the supplement was safe, but metabolically inert on every outcome the trial measured (PMID 29992272). A 6-week crossover trial of 30 healthy middle-aged and older adults (24 completed) taking 1,000 mg a day found blood NAD+ rose about 60%, and found systolic and diastolic blood pressure trended lower — but neither change reached statistical significance after the researchers corrected for testing multiple outcomes. A post hoc look at people with higher starting blood pressure showed a larger apparent drop, but the authors were explicit that this was an exploratory subgroup finding from a small study, not a confirmed effect, and called for larger trials before drawing conclusions (PMID 29599478).
A 21-day crossover trial in 12 men with a median age of 75 found NR raised the NAD+ metabolome specifically in skeletal muscle and lowered some circulating inflammatory markers, but produced no measured change in muscle mitochondrial function — the outcome the trial was largely designed to test (PMID 31412242). A separate 8-week trial of 120 healthy older adults tested a combination product containing NR plus pterostilbene, not NR alone, at a standard and a double dose; NAD+ rose about 40% and 90% respectively, with no serious adverse events, but again the trial measured NAD+ and safety, not a clinical outcome, and the result can't be separated out to NR alone (PMID 29184669).
The one trial with a disease population and a clinical signal is also the one that needs the most caveats. A small phase I trial gave 1,000 mg of NR or placebo daily for 30 days to 30 people newly diagnosed with Parkinson's disease. NR safely and significantly raised brain NAD+, measured directly in cerebrospinal fluid and by brain imaging — but only in the subset of people whose brain NAD+ rose did researchers also see altered brain glucose metabolism, and mild clinical improvement associated with it. That's an exploratory finding within a small trial in a specific disease population, not a general result, and the study's own authors describe it as nominating NR for further investigation in larger trials — not as an established treatment for Parkinson's disease or anything else (PMID 35235774).
Questions people ask
What does nicotinamide riboside do?
In every human trial reviewed here, it raises blood or tissue NAD+, in a dose-dependent way. Beyond that biomarker, the trials that measured a further outcome — insulin sensitivity, body composition, blood pressure, mitochondrial function — mostly found no significant effect.
Is nicotinamide riboside good for you?
It's been shown to be safe and well tolerated across every human trial cited on this page, at doses up to 2,000 mg a day for 12 weeks. "Good for you" in the sense of a proven health benefit is a separate question the trials mostly haven't answered yes to.
What is nicotinamide riboside used for?
Most commonly, people take it hoping to support healthy aging or metabolic function by raising NAD+. The trials confirm the NAD+ rise; they don't confirm a resulting change in aging, metabolism, or disease risk in generally healthy people.
What are the benefits of nicotinamide riboside?
The one consistent, well-replicated finding is a dose-dependent rise in blood NAD+. Secondary findings — a possible anti-inflammatory effect, a blood-pressure trend in older adults, a exploratory signal in Parkinson's disease — appear in single or small trials and haven't been confirmed in larger, independent studies.
What does nicotinamide riboside do for the body?
It supplies a building block the body uses to make NAD+, a coenzyme involved in energy metabolism and cellular repair processes. What a higher NAD+ level from a supplement changes downstream, in a healthy person, is the open question this page covers.
Does nicotinamide riboside help with anti-aging?
No human trial has measured an anti-aging or lifespan outcome in people — that claim is extrapolated from animal research and from the NAD+-decline theory of aging, which a 2019 human trial specifically notes is thin on human data (PMID 31412242).
When to talk to a doctor
A metabolic condition like insulin resistance or high blood pressure, or a neurological condition like Parkinson's disease, is worth managing with a doctor's involvement, not a supplement. Nicotinamide riboside is not a treatment for any diagnosed disease, and nothing in the research above supports using it as a substitute for medical evaluation or a treatment a doctor prescribes. If you're pregnant, nursing, or take a prescription medication, talk to a doctor before adding any supplement, nicotinamide riboside included.
Sources
- Nicotinamide riboside is uniquely and orally bioavailable in mice and humans The first published human trial of nicotinamide riboside (2016) found single oral doses of 100–1,000 mg produced a dose-dependent rise in blood NAD+ in 12 healthy adults, and that NR behaves differently in the body than the other two forms of vitamin B3.
- Safety and Metabolism of Long-term Administration of NIAGEN (Nicotinamide Riboside Chloride) in a Randomized, Double-Blind, Placebo-controlled Clinical Trial of Healthy Overweight Adults A 2019 randomized, placebo-controlled trial of 140 adults found nicotinamide riboside raised blood NAD+ dose-dependently at 100-1,000 mg/day over 8 weeks with no reports of flushing and no rise in LDL cholesterol or homocysteine, unlike the other forms of vitamin B3.
- Chronic nicotinamide riboside supplementation is well-tolerated and elevates NAD(+) in healthy middle-aged and older adults A 2018 crossover trial's discussion explains that niacin's flushing reaction comes from binding a specific skin receptor (GPR109A) that nicotinamide riboside isn't expected to activate, and found flushing reports were, if anything, more common on placebo than on NR.
- A randomized placebo-controlled clinical trial of nicotinamide riboside in obese men: safety, insulin-sensitivity, and lipid-mobilizing effects A 2018 trial of 40 obese men given 2,000 mg/day of NR for 12 weeks found no improvement in insulin sensitivity, glucose metabolism, or body composition compared with placebo, though it was safe and well tolerated.
- Nicotinamide Riboside Augments the Aged Human Skeletal Muscle NAD(+) Metabolome and Induces Transcriptomic and Anti-inflammatory Signatures A 2019 crossover trial of 12 men in their mid-70s found NR raised the muscle NAD+ metabolome and lowered some circulating inflammatory markers over 21 days, but did not change measured muscle mitochondrial function; the paper notes human aging-related NAD+ decline data are sparse compared with animal research.
- Repeat dose NRPT (nicotinamide riboside and pterostilbene) increases NAD(+) levels in humans safely and sustainably: a randomized, double-blind, placebo-controlled study A 2017 trial of a nicotinamide-riboside-and-pterostilbene combination product in 120 older adults found dose-dependent NAD+ increases (about 40% and 90% at two doses) over 8 weeks with no serious adverse events — a combination-product result, not one isolating NR alone, and no clinical outcome beyond NAD+ was measured.
- An open-label, non-randomized study of the pharmacokinetics of the nutritional supplement nicotinamide riboside (NR) and its effects on blood NAD+ levels in healthy volunteers An 8-person, open-label pharmacokinetics study found NR roughly doubled blood NAD+ at steady state with no reported adverse events — a small, uncontrolled study measuring a biomarker, not a clinical outcome.
- The NADPARK study: A randomized phase I trial of nicotinamide riboside supplementation in Parkinson's disease A small phase I trial in 30 people newly diagnosed with Parkinson's disease found NR safely raised brain NAD+ over 30 days, with mild clinical improvement only in the subgroup whose brain NAD+ rose — an early, exploratory disease-specific signal the authors say needs larger trials, not evidence NR treats Parkinson's disease or benefits a general population.
- What is really known about the effects of nicotinamide riboside supplementation in humans A 2023 review of the 25 published human nicotinamide riboside studies available at the time found few clinically relevant effects overall and warned that some published claims about NR have exaggerated what the underlying data show.
*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.