Nicotinamide Riboside dosage and evidence
Written by Aaron CuhaReviewed Sep 2026
The short answer
Nicotinamide Riboside is a form of vitamin B3 that reliably raises NAD in people. That part is proven. A big mouse program found it did not help mice live longer.
Evidence grade for Nicotinamide Riboside: Limited. The rule: people have taken it in a published study, but fewer than 100 of them. The sum on this page: 4 completed trials, 90 people given it. A grade counts how much has been done to people, not whether it works.
- People given it
- 90
- Human studies
- 4
- Found nothing
- 1
Dose
No human dose established
Amounts that were given in studies sit in Human evidence on this page. None of them is a personal dose.
4 completed trials, 90 people given it
5 effects reported, 3 unwanted, 2 wanted, by people using it, not a trial
Goal pages: Fat loss and metabolism, Muscle and strength, Ageing and longevity, Gut health
In plain English
In plain English, from Aaron
This is how I would explain it to a friend. The evidence, with the numbers, is further down the page.
Nicotinamide riboside is a form of vitamin B3 that your body turns into NAD+. Of all the NAD boosters, this one has the best proof that it raises the number. It is sold as a supplement, often under the name Niagen. It is not an approved drug.
What people take it for
- Slowing down ageing.
- More energy and better recovery.
- Protecting the brain as they get older.
- Raising an NAD+ number they saw on a test.
What studies in people showed
Raising the number is proven. The question that matters is whether a higher number does anything. In people there is one real result. 90 patients with clogged leg arteries took it for six months. They walked 17.6 metres farther in six minutes than the dummy pill group. That is one study in sick people. It is not proof of anything for a healthy person. Six weeks of it in middle aged and older adults was well tolerated and raised NAD+. An 8 week trial found more dose meant more NAD+. In a small first human study, the pill raised blood NAD+ up to 2.7 times. Nobody has shown this pill slows ageing in a person. In mice, the US government's lifespan programme tested it. The mice did not live longer, male or female. The authors said they had expected it to work.
What people report
Reports, not study results
The good
- Most people say they feel nothing bad on it.
- Some report a small lift in energy.
The bad
- Nausea, flushing, leg cramps and easy bruising. These show up in the trial side effect lists and are mild.
- A lot of people feel no change at all.
- It is expensive for a vitamin.
Where these come from: The side effect list is from the trial safety tables. The energy and no-change reports are from longevity forums and sites that pool user reviews. Those are not from a trial.
My bottom line
This is the best NAD booster at doing the one thing it is sold on, and the mice it was tested on did not live longer. I would not take it to slow ageing.
An opinion, not a finding. I am a coach, not a doctor.
What it has been measured to do
Measured in people
Goals Nicotinamide Riboside has been tested for in people, biggest studies first. We count only what the studies on this page say, so the real numbers may be higher.
- Getting stronger90 people · 1 study
- Cell energy and mitochondriano headcount stated · 4 studies · 1 found nothing
- Blood sugar and insulinno headcount stated · 1 study · 1 found nothing
- Liver fat and liver healthno headcount stated · 1 study
What people using it report
Real people telling you what happened to them. Nobody checked it, and the people who post are not a fair sample, so it cannot prove anything works. It is still the best guide on this page to what people actually do with Nicotinamide Riboside, what they expect, and what goes wrong. The full account, including the negative reports, is below.
Animal and lab work, not yet tested in people
Real results, but from animals or cells, not people. What works in a mouse often does not work the same way in a person. Nobody can patent this, so nobody would ever earn back the cost of a study in people. That is usually why there is none.
- Living longer1 animal or lab study
29 of the 36 indexed goals have no study of any kind behind Nicotinamide Riboside
No study in people, animals or cells on this page reports a result for these. That does not prove Nicotinamide Riboside does nothing for them. It does mean anything you have heard about Nicotinamide Riboside and one of these did not come from a study cited here.
When this earns a spot
Same idea as NMN: the body turns it into NAD. Studies in people exist, and mostly check blood markers and safety, not whether people live longer. It is not a basic-list vitamin.
Bloodwork that belongs beside the bottle
A metabolic panel is optional. Compare the NMN page.
There is no must-do blood test for this one. We say so on purpose.
Test again after about 90 days. If that blood number did not move, stop.
- Do not read a rise in liver enzymes as detox.
- Taking NR with NMN is two receipts, not a better plan.
Reading the number
Same honest answer as NMN. If nothing you can name moved, stop.
What people typically order
No blood test required. What is really in the product still matters.
Show full evidence
What is Nicotinamide Riboside?
Nicotinamide Riboside is a form of vitamin B3 that reliably raises NAD in people. That part is proven. A big mouse program found it did not help mice live longer.
Nicotinamide riboside, or NR, is a form of vitamin B3. The body turns it into NAD, a molecule cells need to make energy and fix damage. Studies in people show NR safely raises NAD. It is sold as a supplement, for example as Niagen. But raising NAD and helping people are two different things. In 90 people with poor blood flow in their legs, six months of NR added 17.6 metres to how far they could walk in six minutes. In 40 obese men, 12 weeks of NR did not improve how their bodies handled insulin. In mice, the US government's ageing test program found NR did not help males or females live longer, even though the researchers expected it to work. Raising NAD is proven. Living longer is not.
How does Nicotinamide Riboside work?
The body turns NR into NAD through a recycling route. That tops up the NAD that falls with age. NAD feeds the parts of cells that make energy and do repairs.
What have studies in people found about Nicotinamide Riboside?
NR reliably raises NAD in the blood. Results on how people actually feel or function are few. One study found a small gain in walking distance in people with poor leg circulation. A careful insulin study in obese men found no change. A big mouse program found no longer life.
- NICE 2024: 90 people with poor blood flow in their legs took NR for 6 months. They walked 17.6 metres further in six minutes than people on a dummy pill.
- Dollerup 2018: 40 obese men took 2000 mg a day for 12 weeks. How their bodies handled insulin did not improve. Neither did their body fat or muscle.
- Conze 2019: healthy overweight adults took it for 8 weeks. It was safe, and bigger doses raised NAD more. The study did not look for a health benefit.
- Trammell 2016 and Martens 2018: NR taken by mouth raises NAD in the blood, and 6 weeks of it was easy to take.
- In mice: the US ageing test program found NR did not help males or females live longer.
What this does not tell you: Raising NAD is easy to show. It is not the same as living longer or handling sugar better. The walking result was in people with poor leg circulation, not in healthy older people. No study has tested whether NR helps people live longer.
What do people who took Nicotinamide Riboside report?
This is what real people say happened to them, good and bad. Nobody measured it. A report cannot tell a real effect from the lift people get just from expecting it to work, from a diet or training change made at the same time, or from what was really in the vial. We still put it near the top. It is the next best thing to a study in people: what happens when real people use it, including what goes wrong.
- The most common report by a wide margin is that nothing noticeable happened. People describe months of use, amounts from a few hundred milligrams up to about 2 g a day, and combinations with other longevity supplements, with no change in what they were tracking including blood pressure.
- The explanations people offer each other for that are dose and age, with a repeated suggestion that any effect would only show in people over a certain age or with an existing problem, which is offered as speculation rather than supported in the threads.
- In testosterone and men's health discussion it is largely dismissed on cost rather than debated on effect, with the argument that oral doses are converted in the liver anyway so that cheap plain niacinamide reaches the same endpoint for a fraction of the price.
- An observation raised in passing is that a manufacturer suggesting a break after a month implies side effects are being reported somewhere, which nobody in the threads is able to resolve.
- Favourable accounts exist but are individual and are not accompanied by measurements. Side effect discussion is thin, which in a supplement forum is an absence of complaints rather than evidence of safety.
Sources: ExcelMale NAD threads read directly, plus LongeCity personal experience threads reached through site-restricted search extracts because that board timed out on direct fetch from this environment, September 2026. Nothing above is attributed to any specific post and no post is reproduced.
The evidence, in charts
Fig. 1a · how many people
90people, across 1 study in people cited here
| Study | People | Share |
|---|---|---|
| Nature Communications 2024 | 90 | 100% |
The whole total is one study of 90. Counts are the number of people each study on this page says it signed up. That includes studies that only watched people and gave nobody the compound. 4 more studies in people give no headcount and are not counted here. Studies still signing people up are left out, and only studies cited on this page are counted.
Fig. 1b · evidence mix
5 of 6 sources here are studies in people. The rest is not.
- Study in people · done in people583%
- Animal study · done in animals117%
Counted from the list of sources on this page. It counts only what we cite, so there may be more studies out there. A review counts once, however many studies it sums up.
Fig. 2 · evidence over time
The studies cover 5 different years, 2016 to 2024, counted from the list of sources on this page.
Fig. 3 · legal status at a glance
US
Not approved
UK
Not approved
AU
Not approved
CA
Not approved
Not approved in any of the four countries shown. This is what the law says, not a verdict on the science. See Legal status below for the full text and any notes.
Fig. 4 · how much does what
Nobody has tested different amounts in people
This chart would show how the effect changes as the amount goes up. For this compound, nobody has measured that in people. So we leave it empty. We will not borrow an animal chart and pretend it works the same in people.
Fig. 5 · what the molecule is
- Kind of compound
- Supplement
- Molecule weight
- 255.2 Da
- Half-life
- Stated in words, not a numbersee the exact wording below
- Chain length
- None on file
No amino acid sequence is on file for Nicotinamide Riboside, which is expected: a supplement is not built from amino acids.
The studies we cite
- Study in people2016Nicotinamide riboside is uniquely and orally bioavailable in mice and humans
Swallowing this form of vitamin B3 really does raise NAD in the blood. In a small human study the level rose by up to nearly three times. That single fact is what the entire NAD supplement industry is built on. Raising a level in the blood is the start of an argument, not the end of it. Nobody in this study got healthier.
Oral NR raised blood NAD+ up to 2.7-fold in a human pilot and showed superior hepatic NAD+ kinetics in mice.
- Study in people2018Chronic nicotinamide riboside supplementation is well-tolerated and elevates NAD+ in healthy middle-aged and older adults
Six weeks of it was comfortable to take, and it lifted NAD as expected. Adults in middle age and older each did a stretch on the supplement and a stretch without it. What was measured was body chemistry. No symptom, no performance test and no disease outcome was looked at here.
Randomized crossover trial: 6 weeks of NR was well tolerated and effectively stimulated NAD+ metabolism.
- Study in people2019Safety and metabolism of long-term administration of NIAGEN (nicotinamide riboside chloride) in a randomized, double-blind, placebo-controlled clinical trial of healthy overweight adults
Eight weeks of it was safe in healthy overweight adults, and larger doses raised NAD further. Some people got the supplement and some got a dummy pill. The study was built to check safety and find a dose, and that is what it answered. It was not built to show a benefit, and it did not show one.
8-week dose-ranging RCT supporting safety and dose-dependent NAD+ elevation.
- Study in people2024Nicotinamide riboside for peripheral artery disease: the NICE randomized clinical trial
For the first time, this supplement changed something a person could actually do. 90 patients with poor circulation in their legs took it for six months. They could walk about 17.6 metres further in six minutes than the dummy group, which is around 20 extra paces. That is modest, and it is real. It is also the only result this compound has that is about function rather than chemistry.
90 patients: 6 months of NR improved 6-minute walk distance by 17.6 m versus placebo, a first functional outcome.
- Study in people2018A randomized placebo-controlled clinical trial of nicotinamide riboside in obese men: safety, insulin-sensitivity, and lipid-mobilizing effects
In obese men, it did not help. 40 inactive men with a BMI over 30 took 1000 mg twice a day, or a dummy pill, for 12 weeks. A careful test of how their bodies handled insulin showed no change. Neither did how they burned fuel, their body fat or muscle, or the fat in their liver. It was safe. Raising NAD in a mouse and fixing insulin in a man turned out to be different things.
40 obese insulin-resistant sedentary men, BMI over 30, aged 40 to 70, randomised to NR 1000 mg twice daily or placebo for 12 weeks. Insulin sensitivity by hyperinsulinaemic euglycaemic clamp, endogenous glucose production, glucose disposal, resting energy expenditure, lipolysis and body composition did not improve. Safe. NCT02303483.
- Animal study202117-a-estradiol late in life extends lifespan in aging UM-HET3 male mice; nicotinamide riboside and three other drugs do not affect lifespan in either sex
In mice: the US government's ageing test program gave NR to mice from 8 months old. Males and females did not live any longer. The researchers noted they had expected it to work.
NIA Interventions Testing Program: nicotinamide riboside at 1000 ppm from 8 months did not increase lifespan in either sex. The authors note this came despite data suggesting it would be effective.
Common questions
Has Nicotinamide Riboside been tested in people?
Yes. 90 people given it across 4 completed trials cited here, 1 of which found nothing. Nicotinamide Riboside is a form of vitamin B3 that reliably raises NAD in people. That part is proven. A big mouse program found it did not help mice live longer.
What is the Nicotinamide Riboside dosage?
No human dose established. Amounts that were given in studies sit in Human evidence on this page. None of them is a personal dose. 4 completed trials, 90 people given it
Is Nicotinamide Riboside FDA-approved?
Sold as a supplement; not an approved drug
Is NR better than NMN?
Both raise NAD. NR has more published studies in people on safety and NAD levels, and its status as a supplement is clearer. NMN's legal status in the US is in dispute. Neither one is proven to help you live longer.
Latest reading on Nicotinamide Riboside
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