What are NMN supplements? We asked an expert if they can really slow aging and more

The anti-aging coenzyme craze is no longer reserved for A-listers and biohackers.By now, most of us have heard about nicotinamide adenine dinucleotide, better known as NAD.NAD is a cellular compound found in all living organisms.

It plays a critical role in hundreds of bodily functions, including supporting cellular health, energy production and DNA repair.Research also indicates that NAD levels decline in human brains with age, which has prompted more people to look into various NAD-boosting treatments.Celebs have been seen with their NAD+ IV drops, while longevity enthusiasts have explored different supplements, from powders to pills.However, understanding NAD requires understanding NMN (nicotinamide mononucleotide), its immediate precursor.

Researchers have spent years studying the relationship between NMN and NAD.Dr.Andrew Salzman, a physician from Harvard Medical School and Chief Medical Officer of wellness biosciences company Wonderfeel, has emphasized that the key to restoring NAD levels may not be NAD itself — but the compounds that help the body produce it.Unlike the larger NAD molecule, NMN is smaller.

Scientists like Salzman believe NMN has greater potential for uptake into certain tissues throughout the body.Once inside the cell, NMN can easily convert into NAD, helping replenish the body’s levels of the essential cellular compound.While NMN is well-researched, it has not always been widely available online.In 2022, the FDA banned the marketing of NMN as a dietary supplement while it was still being investigated as a drug.

But in 2025, the FDA reversed its position, allowing NMN supplements to re-enter the market.Today, thousands of brands offer NMN supplements in a variety of formulas and formats, with different standards for testing and production.Since NMN is a relatively new addition to the longevity supplement space, many people may be wondering what to look for when choosing a high-quality NMN supplement in 2026 — as well as the proper d...