Who discovered NAD? Arthur Harden and William John Young identified its activity while studying yeast fermentation, the process that turns sugar into alcohol. Their detailed 1906 paper described a helper that survived boiling. Later researchers worked out its structure, its vitamin connections and its role in aging biology.
The discovery came from a question about yeast, long before today's interest in NAD+ treatments.
Who discovered NAD in yeast juice?
Harden and Young worked at the Lister Institute in London. They were trying to understand why yeast juice lost its ability to ferment sugar. One idea was that enzymes, the proteins that make chemical reactions happen, were being broken down.
They added boiled yeast juice to an active preparation and saw fermentation increase. Boiling had destroyed some working parts, but something useful survived. Further separation showed that two fractions, meaning portions of the original liquid, needed each other for fermentation.
That helper became known as a coenzyme: a small molecule an enzyme needs to do its job. NAD's story began with evidence of a helper's activity, rather than a bottle of the purified molecule.
Their 1906 coferment paper's abstract explicitly builds on an earlier communication. Harden later described the boiled-juice experiment in his 1929 Nobel lecture. So 1906 marks a detailed publication in a discovery that unfolded over several experiments.
Cozymase, the NAD name and the 1929 Nobel
The early paper used coferment. Cozymase came later; Harden credited that name to Hans von Euler-Chelpin. It described the helper accompanying the yeast's fermentation machinery.
Today, NAD stands for nicotinamide adenine dinucleotide. Dinucleotide means two connected nucleotide units, small chemical building blocks.
The plus sign marks the form ready to accept electrons, tiny charged particles transferred in chemical reactions. NADH is the form carrying them. That chemistry differs from a peptide, a chain of protein building blocks. Our explanation of why NAD isn't a peptide covers the distinction.
Harden and von Euler-Chelpin shared the 1929 Nobel Prize in Chemistry for work on sugar fermentation and its enzymes. Young helped make the discovery but wasn't one of that year's laureates. The prize recognized basic chemistry, without establishing a treatment benefit.
The 1930s: Warburg, niacin and pellagra
Otto Warburg and Walter Christian, working in Berlin, helped explain how the molecule moved hydrogen in chemical reactions. Their 1936 paper examined the hydrogen-carrying part of fermentation coenzymes.
The chemistry involves hydride transfer: moving a hydrogen atom carrying an extra electron. NAD+ receives that package and becomes NADH. That exchange connects the helper discovered in yeast to the way cells process nutrients.
In 1937, Conrad Elvehjem and colleagues at the University of Wisconsin linked niacin, vitamin B3, to black tongue, a deficiency disease in dogs. Human work followed. Tom Spies, Clark Cooper and Marion Blankenhorn published a 1938 JAMA study on niacin treatment for pellagra, a vitamin-deficiency disease affecting the skin, gut and brain.
That is a vitamin-treatment milestone. Niacin supplies material the body uses to make NAD; it isn't an NAD+ injection. Treating a deficiency and giving extra NAD+ to someone without one ask different medical questions.
Kornberg's synthesis and early human reports
Arthur Kornberg's 1948 paper described enzymatic synthesis, meaning assembly with the help of an enzyme, of the molecule then called diphosphopyridine nucleotide. That older name referred to NAD. Researchers were moving from finding the helper to understanding how it could be made.
An early human record appeared in 1961. Paul O'Hollaren published a preliminary report on NAD and drug addiction. Its publication documents early clinical interest. It doesn't establish the broader energy and longevity claims attached to NAD+ today.
The 2000s: how NAD entered longevity research
In 2000, Shin-ichiro Imai and colleagues in Leonard Guarente's MIT laboratory connected NAD to Sir2, a protein involved in yeast aging. Their Nature paper showed that yeast and mouse Sir2 proteins needed NAD for an activity that removes chemical tags from other proteins.
Sir2 belongs to the sirtuins, a family of enzymes involved in regulating cell activity. The finding connected nutrient chemistry with aging research. It didn't test whether NAD+ injections extended human life.
David Sinclair's Harvard research group later helped develop that connection. In a 2013 Cell study led by Ana Gomes, raising NAD+ in old mice changed the function of mitochondria, the cell's energy-producing structures.
Those influential findings involved yeast, proteins studied in the laboratory and mice. Much of the familiar anti-aging story grew from that work. The NAD+ myths guide checks the claims that go beyond what those experiments show.
Human studies ask a narrower question
By 2019, NAD+ itself was being studied during clinic infusions. In a Frontiers in Aging Neuroscience pilot, eight men received NAD+ into a vein over six hours, while three received saline, a saltwater solution. Researchers tracked blood and urine chemicals. They weren't testing lifespan or whether people felt more energetic.
As of September 30, 2026, the day this article was written, a study published September 25 adds a longer human follow-up. Igarashi and colleagues' 24-week npj Aging trial assigned 62 adults aged 65 or older to oral NMN or comparison capsules. NMN, nicotinamide mononucleotide, is an ingredient the body can use to make NAD+.
Blood NAD+ rose, but hearing and physical performance did not significantly improve. The trial tested NMN capsules, so its findings don't establish a benefit from NAD+ injections.
Where NAD+ stands today
Through Promise, NAD+ is dispensed as a compounded injectable medication, prepared by a pharmacy for a prescription after a licensed provider reviews your request. It is different from an FDA-approved product: the formulation offered here is not FDA-approved. FDA explains that it does not verify compounded drugs' safety, effectiveness or quality before marketing.
A February 9, 2026 FDA letter described a repackaged NAD+ injection as an unapproved new drug. Its July 27 close-out said the firm appeared to have addressed the violations. Closing that file doesn't change a compounded preparation's review status.
A licensed provider may still prescribe a compounded formulation; that decision is between you and your doctor.
What the history means for a prescription visit
A century of discovery explains why NAD matters to cells. A visit addresses the separate question of whether a particular treatment fits a particular person.
The discussion includes the goal, medical history, current medications, evidence for the proposed treatment and how unwanted effects would be handled. A licensed U.S. compounding pharmacy prepares prescribed medication, with a label and lot number that identify what was dispensed.
The NAD+ injections overview covers the treatment discussion. At Promise, a licensed provider reviews every request, and not everyone qualifies. The history provides context; the prescribing decision still depends on the person and the evidence for that treatment.
