Do longevity supplements work? What NMN, NR and NAD+ studies show

Some supplements have evidence for specific uses. That does not mean they have been shown to extend human life. For NMN and NR, human studies show that these NAD+ precursors can affect NAD-related measurements, and some trials report particular functional or metabolic findings. The evidence does not establish that taking them makes healthy people live longer.

The most useful question is therefore “Works for which outcome, in which people?” A change in a blood marker, better walking performance in a disease-specific trial, and more years of healthy life are three different results.

What are NAD+, NMN and NR?

NAD+ stands for nicotinamide adenine dinucleotide. It helps cells carry out metabolic reactions and serves as a partner for enzymes involved in cellular processes. NMN, or nicotinamide mononucleotide, and NR, or nicotinamide riboside, are compounds the body can use in pathways that produce NAD+.

That biological role explains scientific interest. It does not mean every product advertised as an “NAD booster” has the same formulation, reaches the same tissues, or produces the same outcome. An ingredient's participation in a pathway is a reason to investigate it, not a complete clinical answer. 2018 human NR trial

What has actually been tested in people?

A randomized crossover study in 24 middle-aged and older adults tested NR over six-week periods. It increased NAD-related measurements and was well tolerated over that study period. The authors called for further trials of possible cardiovascular effects. This was a small, short study; it did not measure whether participants lived longer. Martens and colleagues, 2018

A separate randomized trial in 12 older men found changes in the muscle NAD+ metabolome after 21 days of NR, without an improvement in the measured mitochondrial energy-production function. This is a good illustration of why a laboratory change and an expected benefit should be checked separately. Elhassan and colleagues, 2019

NMN has also been tested. A ten-week randomized study in postmenopausal women with prediabetes who were overweight or obese found improved muscle insulin sensitivity. That is a specific finding in a specific population. It cannot establish diabetes prevention, benefits for everybody, or lifespan extension. Yoshino and colleagues, 2021

There are encouraging functional findings worth following. In the 2024 NICE trial, 90 people with peripheral artery disease were studied for six months. NR improved six-minute walking distance relative to placebo under the trial's prespecified analysis; the investigators said a larger confirmatory trial was needed. This disease-specific result is not a general recommendation for healthy adults. NICE randomized trial

More recent work shows the same need to separate markers from outcomes. A randomized trial published in 2025 tested eight weeks of NR in older adults with subjective cognitive decline or mild cognitive impairment. It reported a change in one Alzheimer's-related blood biomarker, but no improvement on its cognitive assessments. The researchers called for further study. This does not establish treatment or prevention of Alzheimer's disease. 2025 NR cognition trial

Is NMN better than NR?

There is no useful universal winner from those studies. Comparing a positive result in one population with a different endpoint in another trial does not substitute for a direct comparison. Duration, baseline health, sample size and formulation all matter.

Before accepting a ranking, ask whether the products were compared head to head and whether the outcome was something meaningful, such as function, symptoms or disease risk. “Raises NAD+” answers a narrower question than “improves healthy aging.” Our guide to healthspan versus lifespan explains why the distinction matters.

Does a short-term safety result mean lifelong use is safe?

No. “Well tolerated” in a six-week study describes what happened to that small group during that study. It cannot rule out uncommon problems, interactions or effects after years of use. Notice who was excluded from the trial too: a study of selected volunteers may not represent someone taking several medicines or living with a different condition.

This does not make an early trial unhelpful. It tells you which question it can answer. Larger and longer studies are needed to test broader claims and identify less common effects. When a seller cites a study, look for its duration and participants as well as its headline.

Should I copy the dose used in a research paper?

A research dose is part of a supervised protocol, not personalized shopping advice. Investigators choose participants, monitor them and define the outcome they are testing. Copying only the dose does not recreate those conditions.

Bring the ingredient and label to a qualified professional if you are considering a supplement. A useful discussion includes why you want it, how you would judge benefit, your other products, and what would make you stop. Clear goals make it easier to reconsider an expense when evidence or circumstances change.

How should a Canadian shopper evaluate a supplement?

For a natural health product, look for the eight-digit NPN and check it in Health Canada's Licensed Natural Health Products Database. Read the authorized use, ingredient amounts, directions and cautions. A licence applies to the product's recommended conditions of use; it should not be stretched into unrelated promises about longevity. Health Canada: Licensed Natural Health Products Database

Bring the actual label to a pharmacist or clinician when you take medicines or have a health condition. Adding several products at once makes it harder to identify duplicated ingredients or an unwanted effect. The National Institute on Aging also advises checking the science and avoiding ingredients you do not need. NIA: Dietary supplements for older adults

Longevitus' Optimus collection explores NAD+ and cellular wellness as a developing brand direction. It is currently a collection and packaging preview. Final ingredients, directions and availability will be confirmed at launch; the studies above do not establish efficacy for these concepts.

Keep promising research in perspective alongside nutrition and sleep. A thoughtful daily routine can start before a research question has a final answer.

This article is published by Longevitus for education. Research about an ingredient does not establish that a Longevitus product has the same effects. Product ingredients, directions and current availability belong on the product page. For personal medical or treatment questions, consult a qualified health professional.