NAD+ and longevity: the 3 most recent discoveries in science

Few molecules generate as much conversation in the world of longevity as NAD⁺. The good news is that the research no longer stops at mice: in 2025 and 2026, results in humans arrived that answer some very specific questions. Here are the three recent discoveries most worth knowing about.

🧬 Longevity Science · 6 min read · Informational content

First, in two lines: what NAD⁺ is

It's a coenzyme found in every one of your cells, involved in how they obtain energy from food. The body produces it from forms of vitamin B3 called precursors, such as nicotinamide riboside (NR), nicotinamide mononucleotide (NMN) and nicotinamide.

Discovery 1: the microbiota decides much of the effect

In January 2026, Nature Metabolism published the first direct comparison in humans of three precursors. In 65 healthy adults, NR and NMN raised blood NAD⁺ comparably over 14 days, whereas nicotinamide did not do so in a sustained way.

The most interesting part was the mechanism: gut bacteria converted NR and NMN into nicotinic acid, which turned out to be the compound that raised blood NAD⁺ the most. In other words, your microbiota could influence how much you benefit from these precursors. (The study was funded by Nestlé Research, as its authors declare.)

Discovery 2: measuring blood NAD⁺ doesn't reveal your biological age

Seven groups of people across Europe, measured using a highly rigorous laboratory method, showed something that contradicts a widespread belief: blood NAD⁺ stays stable with age and doesn't change with lifestyle habits; it only rose when people took NR. The work was published in Nature Metabolism in May 2026.

So it's worth being wary of tests that promise to calculate your “cellular age” from blood NAD⁺. What happens in muscle or in the brain remains an open question.

Discovery 3: NR and memory, an honest result

A pilot trial published in Alzheimer's & Dementia in 2026 studied older adults with mild cognitive impairment. Over 12 weeks, 42 people took NR or a placebo.

• NR was well tolerated and doubled blood NAD⁺.
• It did not improve memory or cognitive function, which was the primary endpoint, nor overall cerebral blood flow.
• An exploratory analysis found a possible increase in blood flow in the hippocampus, a key area for memory, which will need to be confirmed with longer studies.

This is a result worth reporting as it stands: raising NAD⁺ doesn't automatically translate into noticeable changes, at least not within 12 weeks.

What we're learning

• NR and NMN do raise blood NAD⁺, with the microbiota playing a leading role.
• Blood NAD⁺ doesn't work as a clock for ageing.
• The benefits in humans are still being researched, with mixed results calling for longer studies.

If you'd like to discover the NR we formulate at LifeXpan, here's NR PURO.

This product is not a medicine. Use of this product is the responsibility of whoever recommends it and whoever uses it. This article is for informational purposes only and does not replace consultation with a health professional.