NMN, NAD+ and Resveratrol: What Is the Evidence?

The longevity supplement market rests on a simple story. NAD+ is a molecule the body uses. One study reports that it declines with aging in animal models. The pitch follows. Raise NAD+ with a precursor such as NMN or nicotinamide riboside. Or switch on an enzyme called SIRT1 directly with resveratrol. Either way, you should slow aging.

It is a clean story. This page asks a narrower question: what has actually been shown in people?

A 2023 review in Science Advances read all 25 published human trials of nicotinamide riboside. The trials ran from 2 hours to 6 months. Groups were small. The review says oral nicotinamide riboside "has displayed few clinically relevant effects." It also says there is a tendency in the literature to exaggerate the importance of reported effects.

What individual trials found is mixed at best:

• A 12-week trial in 40 obese men gave 2,000 mg a day. The authors report that insulin sensitivity, glucose production, and glucose disposal and oxidation were "not improved.".
• A 21-day crossover trial in 12 older men raised the muscle NAD+ metabolome "without altering mitochondrial bioenergetics." The number went up. The thing the number is meant to stand for did not change.
• A 2018 crossover trial (2 x 6 weeks) raised NAD+. Systolic blood pressure tended to fall by 3.9 mmHg. That change was not statistically significant after correction for multiple comparisons. The authors said future trials should look at blood pressure and arterial stiffness.
• A 2021 Science trial of NMN in prediabetic women was challenged in a comment in the same journal. The comment says the 13 women given NMN had liver fat of 6.3%, and the 12 on placebo had 14.8%. It concludes "this was not an effectively randomized trial.".

Raising a biomarker is not the same as improving health.

Resveratrol is a plant polyphenol. It was claimed to be a direct activator of the SIRT1 enzyme. A 2009 laboratory study reported that this finding might be an experimental artifact. It concluded that resveratrol's effects are "unlikely to be mediated by a direct enhancement of the catalytic activity of the SIRT1 enzyme."

That is one laboratory study. It does not tell you what resveratrol does in people.

This is why a cancer charity is writing about longevity supplements at all.

Tell your oncology team what you take. Bring the actual bottles to the appointment, not a list from memory. The National Cancer Institute says cancer patients should inform their doctors about any dietary supplement they use.

NCI says antioxidant supplements should be used with caution. NCI reports that some studies found worse outcomes in people who took antioxidant supplements during cancer therapy, especially smokers. It also reports that antioxidants promoted tumor growth and spread in tumor-bearing mice. Whether NAD+ boosters count as antioxidants is not something we can tell you. Ask your team.

One animal finding is worth knowing about. A 2023 laboratory study built a probe to image how cells take up nicotinamide riboside. It then used the probe in an animal model of triple-negative breast cancer. The authors report that nicotinamide riboside supplementation led to a significant increase in cancer prevalence and in spread of the cancer to the brain. This was an animal study, not a human one.

We are not telling you that NAD+ boosters cause or worsen cancer in people. Nobody has shown that. We are telling you that the human evidence is thin, a signal exists in animals pointing the wrong way, and "unstudied" is a poor reason for confidence when you are being treated for cancer.

The FDA keeps a public list of new dietary ingredient notifications. It shows two NMN entries. One was submitted on November 17, 2025, with an FDA response on January 28, 2026. The other was submitted on February 11, 2026, with a response on April 17, 2026. The list does not say what the responses were.

A notification is a filing by the company. An FDA response is not a verdict that the ingredient works. The FDA says it does not approve dietary supplements before they are marketed and does not test them before they are sold.

These compounds might turn out to do something. But here is the human evidence as of now. Small, short trials. Mostly markers rather than health outcomes. At least one formally challenged result. And a 2023 review that found few clinically relevant effects.

If you are spending money on this, spend it knowing that is what you are buying. If you are in cancer treatment, have the conversation with your team first.

• PubMed — What is really known about the effects of nicotinamide riboside supplementation in humans (Science Advances, 2023).
• PubMed — A randomized placebo-controlled clinical trial of nicotinamide riboside in obese men: safety, insulin-sensitivity, and lipid-mobilizing effects.
• PubMed — Nicotinamide riboside augments the aged human skeletal muscle NAD+ metabolome (Cell Reports, 2019).
• PubMed — Chronic nicotinamide riboside supplementation is well-tolerated and elevates NAD+ in healthy middle-aged and older adults (Nature Communications, 2018).
• PubMed — Comment on "Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women" (Science, 2021).
• PubMed — A bioluminescent probe for nicotinamide riboside uptake, including the triple-negative breast cancer animal model (Biosensors and Bioelectronics, 2023).
• PubMed — Resveratrol is not a direct activator of SIRT1 enzyme activity (2009).
• FDA — Submitted 75-Day Premarket Notifications for New Dietary Ingredients.
• FDA — Questions and Answers on Dietary Supplements.
• National Cancer Institute — Antioxidants and Cancer Prevention.

Educational information, not medical advice. Do not start, stop or change any medication or supplement because of a web page — including this one. If you are on cancer treatment, tell your oncology team about everything you take, including supplements. Spotted an error? Please email corrections@cancerexplained.org or use /corrections.