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NAD+ Precursor

NRNicotinamide Riboside

The first orally bioavailable NAD+ precursor to reach market.

Nicotinamide riboside (NR) is a pyridine-nucleoside form of vitamin B3. It is the most-studied oral NAD+ precursor in humans, with more than a dozen placebo-controlled trials demonstrating sustained elevation of blood NAD+ at doses between 100 mg and 1,000 mg daily.

What are the pharmacokinetics of NR?

Half-life
~2.7 hours (plasma NAD+ response)
Time to peak (Tmax)
1-2 hours
Clearance
Hepatic phosphorylation to NMN by NRK1/2

NR is largely broken down to nicotinamide in the gut, then reassembled. A fraction reaches tissues intact via NRK2 in skeletal muscle.

What doses of NR have been studied?

Typical use

300-600 mg/day

Clinically studied

100 mg – 2,000 mg/day in published trials

Safety ceiling

2,000 mg/day tolerated in 8-week trial (Conze et al. 2019)

How can NR be delivered?

Oral CapsuleOral Powder

Which mechanisms does NR affect?

The Salvage Pathway

NAMPT recycles nicotinamide back into NAD+

Preiss-Handler Pathway

Niacin enters NAD+ biosynthesis without salvage

Sirtuins (SIRT1-7)

NAD+-dependent deacylases governing cellular stress

What does the research on NR show?

  1. Nature Communications · 2016 · PMID 27721479

    Nicotinamide riboside is uniquely and orally bioavailable in mice and humans

    Trammell SAJ, et al.

    First human pharmacokinetic data showing NR raises blood NAD+ ~2.7-fold at 1 g oral dose, without flushing.

    Read summary

  2. Cell Reports · 2019 · PMID 31412242

    Nicotinamide riboside augments the aged human skeletal muscle NAD+ metabolome

    Elhassan YS, et al.

    21-day NR at 1 g/day raised skeletal muscle NAD+ in aged men and shifted mitochondrial gene expression.

    Read summary

Frequently asked questions

Is NR or NMN better for raising NAD+?
Both reliably raise blood NAD+ at studied doses. NMN has a dedicated intestinal transporter (Slc12a8) and higher sublingual bioavailability, while NR has the longer human safety record and the most published placebo-controlled trials. Neither has been shown superior in head-to-head human data.
What is the optimal NMN or NR dosage?
Published human trials use 250-1,000 mg/day for both NMN and NR. The dose-response for NAD+ elevation plateaus around 500-600 mg/day in most studies — higher doses raise blood NAD+ further but with diminishing tissue-level returns. There is no established clinical dose for longevity outcomes.
Is long-term NAD+ supplementation safe?
Short-term (up to 12 weeks) NMN and NR supplementation at studied doses shows a favorable safety profile with no serious adverse events in published trials. Long-term (multi-year) human safety data does not yet exist. Known considerations include methyl donor depletion, potential sirtuin inhibition at very high nicotinamide doses, and unclear interactions with some chemotherapies.
Should NMN be taken sublingually or orally?
Sublingual NMN bypasses gut degradation and first-pass liver metabolism, producing faster and higher peak plasma concentrations than oral capsules in the available human pharmacokinetic data. For most users, sublingual routes deliver more NMN to tissues per milligram dosed — though oral remains cheaper and more convenient.
Is IV NAD+ worth it?
IV NAD+ rapidly raises plasma NAD+ to supraphysiological levels, but the available research shows most of this is cleared or degraded before reaching intracellular compartments. Clinics report subjective benefits for fatigue and recovery; controlled efficacy trials are sparse. Cost ($300-800 per session) is significantly higher than oral precursor protocols.