tuneTypical Dose
250–300 mg
Vitamin
NR
Nicotinamide riboside
Evidence TierBWADA NOT PROHIBITED
watchEffect Window
NAD+ levels peak within weeks. Functional outcomes require long-term use.
check_circleCompliance
WADA NOT PROHIBITED
Overview
Clinical Summary
Nicotinamide riboside is a vitamin B3-related compound that increases NAD biomarkers. It is used for mitochondrial function and metabolic health goals, especially in aging-related energy decline contexts.
Human studies consistently show NR increases NAD biomarkers, but downstream clinical benefits remain mixed. A newer crossover trial in older adults with subjective cognitive decline or mild cognitive impairment found no clear cognitive improvement over 8 weeks, even though pTau217 moved in a favorable direction. That supports NR as a biomarker-active aging supplement, not as a proven cognition enhancer.
Highly efficient NAD+ precursor that bypasses the rate-limiting step of the B3 salvage pathway, supporting sirtuin activation and mitochondrial biogenesis.
Outcomes
What This Is Expected To Influence
Primary Outcomes
- Reliably and safely increases whole-blood NAD+ levels in humans
Secondary Outcomes
- Minor reductions in systemic inflammation
- Mild reduction in systolic blood pressure and aortic stiffness
Safety
Contraindications and Interactions
Contraindications
- Active cancer (theoretical)
- Pregnancy
- Lactation
Side effects
- Mild nausea
- Flushing
- Headache
Interactions
- PARP inhibitors
Avoid if
- Active malignancy
- Concurrent PARP inhibitor therapy
Evidence
Study-level References
nr-SRC-001RCT Crossover
Sourceopen_in_newMartens CR, et al. "Chronic nicotinamide riboside supplementation is well-tolerated and elevates NAD+ in healthy middle-aged and older adults." Nat Commun. 2018.
Population: Healthy middle-aged and older adults
Dose protocol: Source-listed
Key findings: NR was well-tolerated and effectively stimulated NAD+ metabolism. It produced a mild reduction in systolic blood pressure and aortic stiffness.
Paper content
NR was well-tolerated and effectively stimulated NAD+ metabolism. It produced a mild reduction in systolic blood pressure and aortic stiffness.
nr-SRC-002Randomized controlled crossover trial
Sourceopen_in_newCognitive and Alzheimer's disease biomarker effects of oral nicotinamide riboside (NR) supplementation in older adults with subjective cognitive decline and mild cognitive impairment. Alzheimers Dement (N Y). 2025. doi:10.1002/trc2.70023. PMID:39817194.
Population: Older adults with subjective cognitive decline or mild cognitive impairment.
Dose protocol: 1 g/day oral nicotinamide riboside for 8 weeks in older adults with subjective cognitive decline or mild cognitive impairment
Key findings: NR was safe and reduced pTau217 versus placebo, but RBANS and other cognitive outcomes did not improve significantly.
Notes: This is the best modern corrective study for avoiding overbroad brain-health claims.
Paper content
Oral nicotinamide riboside was safe over 8 weeks and reduced pTau217 versus placebo in older adults with subjective cognitive decline or mild cognitive impairment, but it did not improve global cognition. This is an important modernization study because it supports biomarker activity while correcting overbroad brain-performance claims.