Evidence-based·Last reviewed May 30, 2026·How we grade evidence

Nicotinamide Riboside

VitaminVitamin B3 formBest in the morning

Useful mainly for people specifically wanting to raise NAD+ levels.

Quick decision guide

May help most

people specifically wanting to raise NAD+ levels

Common dosing range

250-500 mg/day

When to expect effects

Weeks (for NAD+ rise)

Watch out for

clinical benefits beyond raising NAD+ are unproven

What is it

Nicotinamide riboside (NR) is a form of vitamin B3 and a direct precursor to NAD+ (nicotinamide adenine dinucleotide), a coenzyme that every cell uses for energy metabolism and many repair and signalling processes. It occurs in trace amounts in milk and is sold as a supplement, most commonly under the branded ingredient name Niagen, marketed to raise NAD+ levels, which decline with age. NR is closely related to nicotinamide mononucleotide (NMN); both feed into the same NAD+ salvage pathway.

Is it worth it for you?

Use this as a quick fit check, not a diagnosis.

Worth considering if…

You specifically want to raise blood NAD+ levels
You want a non-flushing form of vitamin B3
You accept that downstream benefits are unproven

Probably skip if…

You expect proven anti-aging or disease prevention
You are pregnant or breastfeeding
You are undergoing cancer treatment without oncologist input

Evidence at a glance

raising NAD+ levels

Good Evidence
Effect
Dose-dependent increase in blood NAD+
Best fit
Adults wanting to increase NAD+, which declines with age
Time
Weeks

metabolic health and insulin sensitivity

Mixed Evidence
Effect
Modest and inconsistent
Best fit
Not clearly established; studied in metabolically at-risk adults
Time
Weeks to months

Evidence for 2 uses

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

raising NAD+ levels

Biomarker support
Good Evidence

Human RCTs consistently show oral NR raises blood NAD+ in a dose-dependent way via the NAD+ salvage pathway. This is a biomarker change, not a clinical outcome: a higher NAD+ level has not by itself been shown to produce symptom relief or disease prevention.

Effect size
Dose-dependent increase in blood NAD+
Time to effect
Weeks
Best fit
Adults wanting to increase NAD+, which declines with age

Bottom line: NR reliably raises blood NAD+, but that biomarker shift does not by itself prove a health benefit.

SourceBrakedal et al., 2022 — PubMedMartens et al., 2018 — PMC

metabolic health and insulin sensitivity

Biomarker support
Mixed Evidence

Despite reliably raising NAD+, randomized trials have shown only modest or inconsistent effects on insulin sensitivity and other metabolic measures, varying by population and dose. Higher doses raise NAD+ more without proportionally greater metabolic benefit.

Effect size
Modest and inconsistent
Time to effect
Weeks to months
Best fit
Not clearly established; studied in metabolically at-risk adults

Bottom line: Metabolic benefits are inconsistent in trials despite the NAD+ increase.

Evidence is mixed

Trials reliably raise NAD+ but report mixed effects on insulin sensitivity and metabolism.

SourceDollerup et al., 2018 — PubMed· conflicting
SourceDollerup et al., 2018 — PubMed

How it works

NAD+ is essential for converting food into cellular energy and serves as a substrate for enzymes involved in DNA repair, the stress response, and metabolic regulation, including the sirtuins and PARPs. NAD+ levels fall with age and with metabolic stress, and the central premise of NR supplementation is to replenish them. NR enters cells and is converted to nicotinamide mononucleotide by the enzyme nicotinamide riboside kinase, and then to NAD+, providing an efficient route into the NAD+ salvage pathway. Human trials consistently show that oral NR raises blood NAD+ levels in a dose-dependent way, confirming that it does what it is designed to do biochemically. Whether this translates into clinical benefits is less settled. In animal models, restoring NAD+ improves metabolic, cardiovascular, and neurological measures. In people, randomised trials have reliably demonstrated the NAD+ increase but have shown only modest or inconsistent effects on outcomes such as insulin sensitivity, physical performance, blood pressure, and inflammation, with results varying by population and dose.

How to take it

1. Typical dose
250-500 mg/day
2. Higher studied dose
Up to 1000-2000 mg/day in short-term studies
3. Timing
Once daily, often in the morning (no strong evidence morning is superior)
4. With food
With or without food
5. How long to try
Ongoing; benefits relate to sustained NAD+ so daily consistency matters

What to track

Tolerability (nausea, headache)
Any subjective energy change
Cumulative vitamin B3 intake from all sources

2 commercial forms

Compare the main delivery options and what they’re best suited for.

Nicotinamide riboside chloride (Niagen)

The most common and best-studied commercial form, a stabilised chloride salt used in the majority of human trials.

Orally bioavailable and reliably raises blood NAD+ in a dose-dependent manner.

Nicotinamide mononucleotide (NMN, related precursor)

A closely related NAD+ precursor one step further along the salvage pathway; an alternative rather than a form of NR itself.

Also raises NAD+; head-to-head superiority over NR is not established.

Safety

Know the common side effects, key cautions, and who should avoid it.

Common side effects

NauseaFatigueHeadacheDigestive upset

Who should avoid it

  • Pregnant or breastfeeding people
  • People on cancer therapy without oncologist input

Pregnancy & breastfeeding

Safety in pregnancy and breastfeeding is not established; best avoided.

Interactions

Other high-dose vitamin B3 productsMinor

Cumulative niacin-equivalent intake can become excessive

Cancer therapyMinor

Theoretical concern since NAD+ supports DNA-repair enzymes; discuss with oncologist

Food sources

Cow's milk

Amount
trace amounts (a natural source)
%DV
—

Brewer's yeast

Amount
small amounts
%DV
—

Other vitamin B3 sources (meat, fish, legumes)

Amount
provide niacin and nicotinamide rather than NR specifically
%DV
—

Choosing a product

What to look for on the label — and what to be skeptical of.

Look for…

Clearly stated NR dose in mg
Recognized branded ingredient (e.g., Niagen) for verified content
Third-party purity testing

Be skeptical of…

Reverses aging
Proven to extend lifespan
Boosts energy as a guaranteed clinical effect

Frequently asked questions

What is the difference between NR and NMN?⌄

Both nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN) are precursors that raise NAD+. NR is converted into NMN inside the cell, so NMN is one step further along the pathway. Both reliably increase NAD+ in studies; neither is clearly proven superior in humans.

Does NR cause flushing like niacin?⌄

No. Unlike nicotinic acid (the flushing form of niacin), nicotinamide riboside does not typically cause the skin flushing reaction, which is one reason it is a popular NAD+ precursor.

Does raising NAD+ actually do anything I can feel?⌄

NR reliably raises NAD+ in the blood, but human trials have shown only modest or inconsistent effects on outcomes like metabolism, blood pressure, and performance. Many people notice no obvious subjective change.

Is NR proven to slow ageing?⌄

No. The idea is based on the age-related decline of NAD+ and on animal studies. There is no human trial evidence that NR extends lifespan or healthspan in people.

What dose is typically used?⌄

Commercial products often provide 300 to 500 mg per day, and clinical studies have used 250 to 1000 mg per day (sometimes higher for short periods). More raises NAD+ further but has not shown proportionally greater benefit.

References by claim

raising NAD+ levels

Brakedal et al., 2022 — PubMed (2022) link

Martens et al., 2018 — PMC (2018) link

metabolic health and insulin sensitivity

Dollerup et al., 2018 — PubMed (2018) link

Track Nicotinamide Riboside with Pilora

Set up dose reminders, check interactions, and join the community in the Pilora iPhone app.

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Evidence-based·Last reviewed May 30, 2026·Evidence current as of May 30, 2026·How we grade evidence

Disclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you’re pregnant, breastfeeding, on medications, or managing a chronic condition.