NAD+ Precursors (NMN and NR)
Evidence grade 1 of 5, Untested. Read how the Atlas grades evidence.
Human RCTs (NIAGEN and NMN pharmacokinetic/safety studies) consistently show NMN and NR are safe and raise blood NAD+ levels, but no human trial has shown an effect on lifespan or major clinical aging outcomes, so the specific longevity claim remains theoretical/preliminary despite good animal healthspan data.
Reference only. Not medical advice.
NAD+ is a coenzyme required for hundreds of cellular reactions, including energy metabolism, DNA repair, and the activity of sirtuins, a family of proteins linked to stress resistance and, in model organisms, longevity. NAD+ levels measurably decline with age in blood and tissues, which has motivated interest in boosting NAD+ using precursor molecules that the body converts into NAD+, primarily nicotinamide mononucleotide (NMN) and nicotinamide riboside (NR), both available as oral supplements. In mice, restoring NAD+ levels with these precursors has improved measures of mitochondrial function, muscle performance, metabolic health, and in some studies extended healthspan, though effects on maximum lifespan are less consistent across studies. Human evidence is still largely limited to safety, pharmacokinetics, and short-term biomarker studies rather than long-term health or survival outcomes. Multiple randomized, placebo-controlled trials, generally small (dozens of participants) and short (weeks to a few months), have found that NMN and NR are well tolerated at doses studied (NMN up to around 1,250 mg/day for weeks, NR up to 1,000 to 2,000 mg/day), reliably raise blood NAD+ metabolome levels in a dose-dependent way, and in some trials showed favorable but modest signals on markers such as walking speed, muscle-related outcomes in older or overweight adults, or exercise performance. No completed human trial has demonstrated an effect on lifespan, and results on broader clinical endpoints such as frailty, cognition, or cardiovascular outcomes remain mixed and preliminary. NR is designated Generally Recognized As Safe (GRAS) in the United States for use in food, giving it a longer track record of regulated human clinical use than NMN, whose US regulatory status has fluctuated: the FDA determined in 2022 that NMN could not be sold as a dietary supplement because it had been developed as an investigational new drug, a decision the FDA reversed in 2025 after industry legal challenges, restoring its lawful supplement status. Current status globally is that NMN and NR remain over-the-counter supplements in most jurisdictions, actively marketed for anti-aging purposes, while the scientific evidence supports that they safely raise NAD+ levels in humans but does not yet establish a proven effect on human healthspan or lifespan. Caveats include inconsistent product quality and dosing in the commercial supplement market, and a persistent gap between the mouse healthspan data and confirmed human clinical benefit.
NAD+ is a coenzyme required for hundreds of cellular reactions, including energy metabolism, DNA repair, and the activity of sirtuins, a family of proteins linked to stress resistance and.
Safety in detail
Short-term human trials report no significant adverse effects at studied doses, but long-term safety data beyond several months, and effects in people with cancer history (given NAD+'s role in cell proliferation), have not been established.
What people get wrong
Nothing recorded here yet. There is almost certainly something people get wrong about this one, and the blank space means we have not written it down, not that the record is clean.
Who profits, and who pushes back
Nobody is named here yet, because we have not done that work on this entry. Read that as unfinished. Somebody almost certainly sells this, and somebody almost certainly disputes it. Assume both until we have checked.
How we got here
NAD (nicotinamide adenine dinucleotide) was first identified in the early 20th century as a coenzyme essential for cellular metabolism; its link to aging biology accelerated after a pivotal 2000 Nature paper by Shin-ichiro Imai, working in Leonard Guarente's MIT laboratory, showed that the yeast longevity protein Sir2 is an NAD-dependent enzyme, establishing the sirtuin-NAD connection central to later longevity research. Through the 2000s and 2010s, researchers including Imai and Charles Brenner demonstrated that NAD+ levels decline with age in multiple tissues and that supplementing precursors like nicotinamide mononucleotide (NMN) and nicotinamide riboside (NR) could raise NAD+ levels and improve markers of healthy aging in mice. Human research followed rapidly: the first human NMN clinical study began in Japan around 2016, and Brenner's group published human data in 2016 showing NR safely raises blood NAD+, launching a wave of commercial NAD-boosting supplements alongside an evolving and at times contested regulatory picture in the United States, where the FDA determined in 2022 that NMN could not be marketed as a dietary supplement due to prior drug-development activity, before reversing that determination in 2025.
What this entry does not yet cover
What follows is unfinished work on our side, not a finding about NAD+ Precursors (NMN and NR). A short entry is not a safe entry.
- Timeline. We have not built the dated record of research and regulatory events.
- Cost and market. We have not documented what it sells for or who sells it.
- Supply chain. We have not mapped where it is made.
- Who uses it. We have not documented the user groups.
- What could change. No forward-looking summary yet.
- How it compares. We have not set it against the alternatives.
- Children and teenagers. We have not checked what is known about younger people.
- What can go wrong. We have not written the risk line for this one. Read the safety section below rather than treating its absence as reassurance.
- Where we land. We have not taken a position on this yet.
- What people take it for. We have not catalogued the claims made for it.