NAD+ is nicotinamide adenine dinucleotide, a molecule cells use in essential biochemical reactions. It is a coenzyme, not a peptide. NAD+ and its reduced form, NADH, help transfer electrons in metabolism. NAD+ is also consumed by enzymes involved in processes such as cellular signaling and DNA-damage responses.

NAD+ is not one interchangeable product category

NAD+, nicotinamide riboside and nicotinamide mononucleotide are different molecules. The latter two are discussed as precursors in NAD-related metabolism. Results from one substance, formulation or route cannot be assigned automatically to another.

A human randomized trial of nicotinamide riboside in obese men measured metabolic outcomes and did not demonstrate improvement in insulin sensitivity under the conditions tested. This is an example of why changing an NAD-related pathway is not equivalent to proving a broad metabolic benefit. Dollerup and colleagues, 2018

What raising a biomarker does and does not mean

A product can change a blood measurement without establishing that it improves daily function, prevents disease or extends life. Tissue-specific measurements may also differ from blood results. Researchers need to establish the relevant biological exposure as well as the outcome.

A randomized pilot study in adults with mild cognitive impairment evaluated nicotinamide riboside and highlighted the distinction between feasibility or safety questions and proof of cognitive benefit. Small pilot studies are useful for designing larger trials, but should not carry the weight of a definitive efficacy claim. Orr and colleagues, 2023

A useful reading rule

Whenever “NAD” appears in a headline, identify the exact intervention, the population and the endpoint. Do not assume oral precursor research validates an infusion, injection, or anti-aging claim. Essential biology is a reason to study a molecule carefully, not evidence that more is always better.