NAD+ Precursors (NR & NMN)
Reliably raise NAD+ in blood — but benefits for aging, energy, or health in people are still unproven.
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What it is
NR (nicotinamide riboside) and NMN (nicotinamide mononucleotide) are forms of vitamin B3 that the body uses to make NAD+, a molecule every cell needs for energy metabolism and repair. NAD+ levels tend to fall with age in some tissues.
How it works
NAD+ is a helper molecule used in energy production and in enzymes involved in DNA repair and cell maintenance, including the sirtuins. Animal studies found that boosting NAD+ improved several markers of aging, which sparked human interest. In people, NR and NMN do raise NAD+ in blood, but whether that meaningfully changes NAD+ in key tissues — or slows aging — hasn't been shown.
What it's been studied for
Commonly taken for healthy aging, energy, and metabolic health.
What the evidence shows
Evidence is solid on one point: human trials consistently show NR and NMN raise NAD+ levels in blood and are well tolerated in the short term. Evidence that this improves outcomes people care about — energy, muscle function, blood pressure, insulin sensitivity, or cognition — is weak and inconsistent, with a few small positive findings and several null results. The key limitation is that trials are small and mostly lasted weeks to a few months, so long-term benefits and safety are unknown.
Who should consider it
Adults interested in healthy aging who are comfortable with experimental, unproven benefits may reasonably try them. People looking for a noticeable boost in energy or a proven anti-aging effect probably shouldn't bother, since human trials haven't delivered that. People with cancer or a history of cancer, and anyone pregnant or breastfeeding, should avoid them unless their provider advises otherwise.
Amounts commonly studied
Studies typically used 250 to 1,000 mg per day of NMN and 250 to 2,000 mg per day of NR, usually for 6 to 12 weeks.
How to take it
Studies typically used a once- or twice-daily dose, often in the morning, with or without food, for 6 to 12 weeks. There's no established best timing or long-term duration. Talk to your provider if you have a medical condition or take several medications, since long-term data are limited.
Forms & absorption
NR and NMN come as capsules and powders; there are no good head-to-head trials showing one is better. Oral NAD+ itself is poorly absorbed, and plain niacin and nicotinamide also feed the same pathways.
Food sources
Foods rich in vitamin B3 — poultry, fish, meat, peanuts, mushrooms, and whole grains — supply building blocks for NAD+. Small amounts of NR occur in milk and of NMN in foods like broccoli, edamame, and avocado, far below supplement doses.
Safety & interactions
Short-term trials report good tolerability; nausea, bloating, headache, or fatigue can occur, and flushing is uncommon compared with niacin. Long-term safety is unknown, and because NAD+ supports cell growth there's a theoretical concern for people with cancer, who should talk to their oncologist first. There's little data in pregnancy, breastfeeding, or children, so avoid use in those groups.
Myths & what it won't do
Myth: raising NAD+ in your blood reverses aging. Reality: NR and NMN reliably raise blood NAD+, but human trials haven't shown that this slows aging or improves health in a consistent way. Myth: IV or oral NAD+ works better than precursors. Reality: oral NAD+ is poorly absorbed, and IV NAD+ lacks good evidence for general wellness claims.
Common questions
- Is NMN better than NR?
- There are no good head-to-head human trials. Both raise blood NAD+ in studies, and neither has clearly outperformed the other on health outcomes.
- Will I feel more energetic?
- Most trials haven't found noticeable improvements in energy or physical function. Some people report feeling better, but that's hard to separate from a placebo effect.
- Is it safe long term?
- Short-term trials look reassuring, but studies mostly lasted weeks to a few months, so long-term safety isn't known.
The amounts listed here are what published research has used — not a prescription or a recommended dose for you. Confirm anything you plan to take with your own healthcare provider, especially if you take medications, are pregnant or nursing, or have a health condition.
Related goals
Research on NAD+ Precursors (NR & NMN)
Recommendations on this page are informed by published research. This is educational information, not medical advice.
- Martens CR, Denman BA, Mazzo MR, et al. Chronic nicotinamide riboside supplementation is well-tolerated and elevates NAD(+) in healthy middle-aged and older adults. Nat Commun. 2018;9(1):1286. View study →Note: Six weeks of nicotinamide riboside was well tolerated and raised NAD+ in healthy middle-aged and older adults; physical benefits weren't established.
- Freeberg KA, Udovich CC, Martens CR, Seals DR, Craighead DH. Dietary Supplementation With NAD+-Boosting Compounds in Humans: Current Knowledge and Future Directions. J Gerontol A Biol Sci Med Sci. 2023;78(12):2435-2448. View study →Note: Reviews human trials: NAD+ precursors raise NAD+ levels, but small, varied studies limit conclusions about real-world benefits.