What NAD+ is, and why almost all its trials are of precursors
In short
NAD+ is a nucleotide cofactor, not a peptide. The solid randomised trials in people are of its precursors — nicotinamide mononucleotide and riboside — not of administered NAD+. The systematic review of what has been published on NAD and NADH gathered ten studies and 489 participants in total.
NAD+ is a nucleotide cofactor present in every cell, essential to oxidative phosphorylation and ATP production, to DNA repair and to calcium-dependent signalling [1].
Something obvious is worth saying up front, because it almost never is: it is not a peptide. It is sold alongside the peptides in this catalogue, but it belongs to an entirely different class of molecule, and its behaviour in the body resembles a vitamin more than a hormone.
What has been tested, and what has not
This is the main point.
Almost all the good trials are of precursors. Nicotinamide riboside and nicotinamide mononucleotide are molecules the body converts into NAD+; the trials most often cited study those, not directly administered NAD+.
- Nicotinamide riboside. A randomised trial in middle-aged and older adults described chronic supplementation as well tolerated and as elevating NAD+ [2].
- Nicotinamide mononucleotide. A study in healthy older men described raised blood NAD and altered muscle function [3]. Another randomised, double-blind, placebo-controlled trial studied NAD metabolism and arterial stiffness after prolonged supplementation [4].
And how much evidence there is on NAD and NADH themselves
A 2024 systematic review searched six electronic databases for randomised clinical trials on NAD+ and NADH as a supplement in humans, and assessed their risk of bias with the Cochrane tool [1].
It found ten studies, with 489 participants in total, spread across very different conditions: chronic fatigue syndrome, older adults, Parkinson's disease, overweight, postmenopausal prediabetes and Alzheimer's disease. Supplementation was described as well tolerated, with clinical results scattered across those conditions.
That figure deserves a calm reading. Ten studies and fewer than five hundred people, spread across six unrelated diseases, is a small and heterogeneous base. It does not mean there is nothing; it means there is not yet a solid answer to any specific question.
What there is not
There is no approved indication for NAD+ as a medicine in the European Union or the United States.
This page describes published literature. It is not medical information, it does not describe a therapeutic use, and it does not replace any healthcare professional.
What to look at when comparing suppliers
- Which molecule exactly it is: NAD+, NADH, nicotinamide mononucleotide or riboside. They are four different things and they do not share evidence.
- Purity for the specific batch, with a certificate you can read before buying.
- Stability and storage. It is a sensitive molecule; the certificate says what was there on the day of analysis, not what survives a warm shipment.
References
- [1] Gindri I.M. et al. (2024). Evaluation of safety and effectiveness of NAD in different clinical conditions: a systematic review. Am J Physiol Endocrinol Metab. PMID 37971292 View source
- [2] Martens C.R. et al. (2018). Chronic nicotinamide riboside supplementation is well-tolerated and elevates NAD(+) in healthy middle-aged and older adults. Nat Commun. PMID 29599478 View source
- [3] Igarashi M. et al. (2022). Chronic nicotinamide mononucleotide supplementation elevates blood nicotinamide adenine dinucleotide levels and alters muscle function in healthy older men. NPJ Aging. PMID 35927255 View source
- [4] Katayoshi T. et al. (2023). Nicotinamide adenine dinucleotide metabolism and arterial stiffness after long-term nicotinamide mononucleotide supplementation: a randomized, double-blind, placebo-controlled trial. Sci Rep. PMID 36797393 View source
This page reports what has been published in the scientific literature about a research molecule. It is not medical information, it does not describe a therapeutic use, and it does not replace any healthcare professional. The product is sold strictly for in vitro research.
