NR (Nicotinamide Riboside)
An NAD+ precursor that helps restore the cellular fuel your body loses with age. Clinically proven to raise NAD+ levels, with growing evidence for longevity and metabolic health.
NAD+ is a molecule every cell in your body needs for energy production, DNA repair, and sirtuin activation. By age 50, your NAD+ levels are roughly half what they were at 20. NR (sold as Niagen) is one of the most-studied ways to restore NAD+ — with clinical trials confirming it raises NAD+ levels by 40–90% in humans.
Good for you if: You're over 35 and interested in longevity, feel fatigued despite good sleep and nutrition, or want to support NAD+ levels alongside sirtuins and DNA repair pathways.
Dive deeper into the researchCommon side effects
- Mild nausea at higher doses
- Flushing (uncommon — more common with niacin)
- May cause mild headache initially
What does NR do?
NAD+ (nicotinamide adenine dinucleotide) is involved in over 500 enzymatic reactions in your body. It's essential for converting food to energy, repairing DNA damage, activating longevity genes (sirtuins), and maintaining healthy cellular function. The problem: NAD+ levels decline steadily with age.
NR is a form of vitamin B3 that your body efficiently converts into NAD+ through the nicotinamide riboside kinase (NRK) pathway. It's the most clinically validated NAD+ precursor, with Niagen holding GRAS status and multiple published human trials.
What can you expect?
- Increased NAD+ levels — 40–90% elevation in blood NAD+ within 2 weeks
- Better cellular energy — more efficient mitochondrial function
- DNA repair support — NAD+ activates PARP enzymes for DNA repair
- Sirtuin activation — NAD+ fuels the sirtuin family of longevity proteins
- Metabolic improvements — early evidence for insulin sensitivity and liver fat reduction
How to take it
300–500 mg per day in the morning. Some longevity practitioners use up to 1,000 mg/day, but most of the clinical benefit is captured at 300–500 mg.
Niagen (by ChromaDex) is the most-studied form. Take with or without food — bioavailability is similar either way.
NR vs NMN
| NR (Niagen) | NMN | |
|---|---|---|
| Human trials | Multiple published RCTs | Growing, fewer published |
| NAD+ elevation | 40–90% | Similar range |
| FDA status | GRAS (Generally Recognised as Safe) | Supplement status disputed in US |
| Absorption | Enters cells via ENT transporters | May convert to NR before absorption |
| Cost | Moderate | Moderate-High |
Both raise NAD+ effectively. NR has more human clinical data. NMN has a larger consumer base and some unique preclinical data. Practically, either is a valid choice — consistency matters more than which one you pick.
Track your NAD+ levels alongside NR supplementation
eterni logs your NAD+ precursors, longevity biomarkers, and retests — so you can see if your intervention is working.
Get early accessFrequently Asked Questions
NR or NMN — which should I take?
Both effectively raise NAD+ levels. NR has more published human clinical trials and FDA GRAS status. NMN has a larger consumer following and some interesting preclinical data. There is an ongoing scientific debate about whether NMN enters cells directly or converts to NR first. Practically, both work — pick one and be consistent.
How do I know if NR is working?
You can test NAD+ levels directly through specialised blood tests (intracellular NAD+ assays from companies like Jinfiniti). Subjectively, people report better energy, improved sleep quality, and better exercise recovery within 2–4 weeks. The deeper benefits (DNA repair, sirtuin activation) are harder to measure directly.
Can I get NAD+ from food instead?
Foods contain very small amounts of NAD+ precursors. Milk contains some NR, and meats contain niacin and tryptophan. But the amounts are far below therapeutic doses. To meaningfully raise NAD+ levels — especially declining levels in middle age — supplementation is necessary.
Does NR cause flushing like niacin?
No. Niacin (nicotinic acid) causes flushing because it activates the GPR109A receptor on skin cells. NR does not activate this receptor, so flushing is not a side effect. This is one of NR's advantages over regular niacin for NAD+ boosting.
How it works in your body
NR enters cells via equilibrative nucleoside transporters (ENTs). Inside the cell, NR kinases (NRK1 and NRK2) phosphorylate it to NMN, which is then converted to NAD+ by NMNAT enzymes. This NRK pathway is distinct from the salvage pathway (used by nicotinamide/niacin) and the de novo pathway (from tryptophan).
The resulting NAD+ serves as a substrate for three key enzyme families: sirtuins (SIRT1-7, which regulate gene expression, metabolism, and DNA repair), PARPs (which repair DNA breaks), and CD38/CD157 (immune signalling enzymes that consume the most NAD+ and increase with age).
What the studies show
- NAD+ elevation: 1,000 mg/day of Niagen raised whole blood NAD+ by 60% after 6 weeks in a placebo-controlled trial
- Safety: Doses up to 2,000 mg/day for 12 weeks showed no serious adverse effects
- Muscle function: Improved mitochondrial membrane potential in aged skeletal muscle (human trial)
- Liver health: Reduced hepatic lipid content in obese adults at 1,000 mg/day
- Cardiovascular: Reduced arterial stiffness and blood pressure in a small preliminary trial
Side effects & safety
- Nausea — The most common side effect at higher doses (1,000+ mg). Taking with food helps. Usually transient.
- Headache — Occasionally reported in the first week. Self-resolving.
- Flushing — NOT a typical side effect of NR (unlike niacin). If you experience flushing, your product may contain nicotinic acid.
- Theoretical cancer concern — NAD+ fuels all rapidly dividing cells, including cancer cells. There's theoretical concern that boosting NAD+ could fuel existing tumours. No clinical evidence supports this, but people with active cancer should discuss with their oncologist.
Who should be cautious: People with active cancer (theoretical concern), those on medications metabolised by the same pathways, and anyone with liver disease (consult doctor first).
Which labs to check
- Intracellular NAD+ — the gold standard (Jinfiniti or similar)
- Liver enzymes (ALT, AST) — to confirm no hepatic stress
- Fasting glucose & insulin — NR may improve insulin sensitivity
- hsCRP — NAD+ supports anti-inflammatory pathways
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eterni connects your lab results, supplements, and retests — so you can see the trajectory, not just a snapshot.
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