SPECIALTY TOPICS · GUIDE
NAD+, NMN and Nicotinamide Riboside: What Research Shows
A plain overview of NAD+, NMN and nicotinamide riboside: what the human trials found, where animal findings stop, the US FDA position on NMN, and safety questions.
Content last updated . This page has not been medically reviewed.
Back to Longevity & Healthy AgingA 2026 systematic review of 113 studies (33 in people, 80 in rodents) found that oral NR and NMN reliably raised NAD-related molecules in human blood or cells. It also found that effects on function, metabolism and other healthspan-related outcomes were mixed, and often null. Its overall conclusion was that clinical benefit for anti-aging or wellness remains inconclusive. [1] That is the honest summary of the field today.
This page is education only. It gives no amounts and no advice to start, stop or change anything. For the details, use the three focused guides linked below.
Evidence labels used here
Approved medicine, established, promising but limited, mixed, insufficient evidence, preclinical (cells or animals only), no good evidence of benefit, evidence of harm and marketing claim. A higher NAD+ level in a blood test is a biomarker, not a health outcome, and a result in mice is not a result in people.The three compounds at a glance
| NAD+ | NMN | NR | |
|---|---|---|---|
| What it is | The molecule itself | A precursor the body can convert | A precursor the body can convert |
| Raises NAD-related blood markers in people | Not tested in outcomes trials for anti-aging | Yes, in several short trials | Yes, in several short trials |
| Health benefit shown in people | Not established | Mixed; no clear anti-aging benefit | Mixed; one large trial in Parkinson disease found worse scores |
| Evidence label | Insufficient evidence | Promising but limited for some metabolic questions; insufficient for aging | Mixed; no good evidence of benefit in the conditions tested so far |
| Detail | NAD+ biology | NMN human evidence | NR human evidence |
What stands out
- NAD+ drips and injections. The 2026 review found no eligible outcomes trials of intravenous or intramuscular NAD+ itself for anti-aging or wellness. [1] A separate 2026 narrative review called the evidence preliminary and insufficient to support routine wellness use, and listed reported effects such as nausea, cramping, flushing and chest discomfort. [2] Label: insufficient evidence.
- Blood levels versus health. In a 14-day trial of 65 healthy adults, NR and NMN raised circulating NAD+ similarly. The study was run by Nestlé employees and measured levels, not health outcomes. [3] In people with mild cognitive impairment, blood NAD+ doubled on NR but cognition did not improve. [4]
- Muscle in older adults. A meta-analysis of randomized trials found the evidence does not support NMN or NR for preserving muscle mass and function in adults whose average age was over 60. [5]
- A large null result. A 2026 phase 3 trial in 410 people with early Parkinson disease found 52 weeks of NR did not help and was associated with worse scores than placebo. This does not prove harm in healthy people. [6]
- US regulation of NMN. In letters dated September 29, 2025, the FDA concluded that NMN is not excluded from the dietary supplement definition. [7][8] The agency also says acknowledging a safety notification is not its own finding that the ingredient is safe. [7] The full story is on the NMN page. Rules elsewhere were not verified here, and laws change; this is not legal advice.
Frequently asked questions
Does NMN or NR slow aging?
Not shown. Human trials show blood NAD+ markers can rise, but effects on health outcomes are mixed or null, and no trial has shown slower aging or longer life in people. [1]
Do NAD+ injections or drips work for anti-aging?
The best available reviews found no eligible outcomes trials of intravenous or intramuscular NAD+ for anti-aging or wellness, and called the evidence preliminary. [1][2]
Is NMN legal to sell as a supplement in the US?
In 2025 the FDA concluded NMN is not excluded from the dietary supplement definition. Companies still have to meet the other requirements, and laws change. This is not legal advice. [7]
Are NMN and NR safe?
In a 2026 meta-analysis of short NMN trials (14 days to 24 weeks), adverse events were not increased, but authors said long-term safety needs larger and longer trials. [9] For NR, a large Parkinson disease trial found worse scores than placebo. [6]
Are NAD+ levels really lower in older people?
It is more complicated than ads suggest. Some measurements, such as brain imaging, show lower NAD+ with age, while a 2026 review noted large human data showing whole-blood NAD+ does not fall with healthy aging alone. See the NAD+ biology guide. [10][2]
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
Who should check first
References
- NAD⁺ supplementation for anti-aging and wellness: A PRISMA-guided systematic review of preclinical and clinical evidence. Ageing Res Rev 2026. NAD⁺ supplementation for anti-aging and wellness: A PRISMA-guided systematic review of preclinical and clinical evidence. Read 2026-10-22.
- Narrative review of intravenous NAD(+) and NAD(+) precursors in wellness and translational medicine. Front Aging 2026. Narrative review of intravenous NAD(+) and NAD(+) precursors in wellness and translational medicine. Read 2026-10-22.
- The differential impact of three different NAD(+) boosters on circulatory NAD and microbial metabolism in humans. Nat Metab 2026. The differential impact of three different NAD(+) boosters on circulatory NAD and microbial metabolism in humans. Read 2026-10-22.
- A phase-II randomized controlled pilot study of nicotinamide riboside supplementation in older adults with amnestic mild cognitive impairment. Alzheimers Dement 2026. A phase-II randomized controlled pilot study of nicotinamide riboside supplementation in older adults with amnestic mild cognitive impairment. Read 2026-10-22.
- The Effect of Nicotinamide Mononucleotide and Riboside on Skeletal Muscle Mass and Function: A Systematic Review and Meta-Analysis. J Cachexia Sarcopenia Muscle 2025. The Effect of Nicotinamide Mononucleotide and Riboside on Skeletal Muscle Mass and Function: A Systematic Review and Meta-Analysis. Read 2026-10-22.
- Nicotinamide Riboside for Patients With Early-Stage Parkinson Disease: The NOPARK Randomized Clinical Trial. JAMA 2026. Nicotinamide Riboside for Patients With Early-Stage Parkinson Disease: The NOPARK Randomized Clinical Trial. Read 2026-10-22.
- US Food and Drug Administration, Human Foods Program. Response to citizen petition from Natural Products Association and Alliance for Natural Health on NMN, docket FDA-2023-P-0872. The posted PDF's date line reads "September 29, 2029," an apparent typo. Read 2026-10-22.
- Venable LLP. FDA Declares Nicotinamide Mononucleotide Is a Dietary Supplement (law-firm summary used only to confirm the September 29, 2025 letter date). Read 2026-10-22.
- Safety and Metabolism-Related Outcomes of Oral Nicotinamide Mononucleotide Supplementation in Adults: A Systematic Review and Meta-Analysis. Nutrients 2026. Safety and Metabolism-Related Outcomes of Oral Nicotinamide Mononucleotide Supplementation in Adults: A Systematic Review and Meta-Analysis. Read 2026-10-22.
- In vivo NAD assay reveals the intracellular NAD contents and redox state in healthy human brain and their age dependences. Proc Natl Acad Sci U S A 2015. In vivo NAD assay reveals the intracellular NAD contents and redox state in healthy human brain and their age dependences. Read 2026-10-22.