NAD+ in 2026: Three Scientific Breakthroughs That Change What We Knew

NAD⁺ is one of the most talked-about molecules in longevity science, and one of the most misunderstood. Three studies published in recent months bring a lot of clarity: which precursors actually raise NAD⁺, what role the gut plays, and why a blood test is not the "aging clock" some promise. Here they are, without the hype.

🧬 Longevity Science · 6 min read · For educational purposes

First things first: what is NAD⁺?

NAD⁺ (nicotinamide adenine dinucleotide) is a coenzyme found in every cell of your body. It takes part in turning food into energy and in cellular maintenance. Your body makes it from several forms of vitamin B3, known as precursors: nicotinamide (NAM), nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN), among others.

1. The gut was the missing piece

A trial published in Nature Metabolism in January 2026 compared three precursors head to head in people for the first time. Sixty-five healthy adults took NR, NMN, nicotinamide or placebo for 14 days.

• NR and NMN raised blood NAD⁺ to a similar extent. Nicotinamide did not produce a sustained increase.
• In the lab, gut bacteria converted NR and NMN into nicotinic acid, another form of vitamin B3, which turned out to be the most potent NAD⁺ booster in blood.
• The authors propose a gut-dependent model: NR and NMN would raise NAD⁺ largely through what our gut microbes do with them.

It is a shift in perspective: gut health may shape how each person responds to these precursors. The study was funded by Nestlé Research, as the authors disclose.

2. Blood NAD⁺ is not an aging clock

You often hear that "NAD⁺ declines with age." A May 2026 study in Nature Metabolism, across seven European cohorts, put that to the test with a rigorously validated method. Whole-blood NAD⁺ stayed remarkably stable with age and did not change with lifestyle interventions, while it did rise with NR supplementation.

The practical takeaway matters: a blood NAD⁺ test is not a marker of your "biological age", nor a way to check whether your habits are working. What happens in other tissues, such as muscle or brain, remains an open question.

3. NR in accelerated aging: Werner syndrome

Werner syndrome is a rare inherited condition in which aging is accelerated and NAD⁺ depletion has been reported. Chiba University (Japan) published a double-blind crossover trial in Aging Cell: each patient took NR or placebo for 26 weeks and then switched.

• No serious adverse events were seen with NR, the main goal of the study.
• Arterial stiffness (CAVI index) improved and the area of skin ulcers decreased.
• Blood creatinine, a marker related to kidney function, went down.

It is a small study in a specific condition, with NR provided by a manufacturer, so the results cannot simply be extended to healthy people. Still, it is one of the first placebo-controlled trials in a human model of accelerated aging.

What the three studies tell us together

• NR and NMN raise blood NAD⁺, and the gut takes part in that process.
• Blood NAD⁺ is not a good indicator of aging: be wary of tests sold that way.
• Possible benefits are being studied in specific populations, with promising but still limited results.

NAD⁺ science is moving fast, and with more rigor every year. If you want to learn about the NR we formulate at LifeXpan, meet NR PURO.

This article is for educational purposes only and is not a substitute for advice from a healthcare professional. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.