What is the controversy surrounding NAD+?
NAD+ supplements raise your NAD+ levels, but whether that translates into any health benefit has not been proven, and in the context of cancer (treatment) there are serious safety questions. Discuss it with your doctor if you have a cancer diagnosis or are undergoing chemotherapy.
NAD+ supplements (such as NMN and NR) demonstrably raise NAD+ levels in multiple tissues in humans, and are described in studies as safe and well tolerated. But higher NAD+ levels are not a goal in themselves: the real question is whether you actually notice any benefit. And that is where the problem lies.
When it comes to measurable health benefits in ageing, the evidence so far is unclear. Studies are small, doses and study durations vary widely, and large independent trials are still lacking. Whether NAD+ supplementation genuinely improves heart function, metabolism or other organ functions in ageing people has not been demonstrated.
A serious safety signal comes from cancer research. In laboratory studies, NMN had the strongest protective effect on pancreatic cancer cells, enhancing their resistance to common chemotherapy regimens; in mouse studies, NAM and NMN similarly conferred this resistance. This effect appeared across multiple mouse models. Broader indications suggest that other cancer types, such as acute myeloid leukaemia, also rely heavily on NAD+ production. Raising NAD+ in people with cancer could therefore fuel that process. There is no evidence that this also occurs in humans, but the signal is serious enough not to ignore.
On top of that, there are fundamental gaps in knowledge. The role of the gut microbiome in converting NAD+ precursors, the existence of separate NAD+ pools in different parts of the cell, and exactly how NAD+ is broken down: all of this is still insufficiently understood. Without that knowledge, it is difficult to apply supplementation in a targeted and safe way.
Finally, there is the issue of conflicts of interest. Several authors of widely cited review articles on NAD+ have financial ties to companies that manufacture or sell these supplements. This makes independent interpretation of the available research findings more difficult.
Claims based on PMID 37068054, 40926126, 39026037, 41724424 and 42514364. Cancer data come from laboratory and mouse research, not from human studies.
Are NAD+ supplements (NMN/NR) worth it?
NMN and NR demonstrably raise NAD+ in your blood and appear to be safe, but whether you will notice any benefit in muscle strength, heart function or memory has not yet been proven in humans. Note also: NR is authorised in the EU as a supplement; NMN is not (yet).
Which supplements or medications are best not combined with NAD+?
The combination of NAD+ supplements, particularly nicotinamide, with platinum-based chemotherapy is the most concrete reason for caution. For other interactions the indications are preliminary, but worth discussing if you use multiple substances.
Does a NAD+ infusion do something that an NMN pill does not?
No study directly compares a NAD+ infusion with an oral NMN pill, so an advantage of the infusion has not been demonstrated. Oral NMN demonstrably raises blood NAD+ levels, but whether you notice any health benefit from this remains unclear for now.
What does a NAD supplement do, and does it work in people?
NAD supplements demonstrably raise NAD levels in your blood, but whether you actually benefit from that remains uncertain. If you want to try them, keep your expectations realistic and choose a dose with the best available evidence behind it.
What is NAD+ and what does it do in your body?
NAD+ is an indispensable molecule for energy, DNA repair and cell maintenance, and its levels measurably decline with age. Whether that decline can be corrected with supplements, and what benefit that would bring, is a separate question.
What does NAD+ do for your brain?
NAD+ matters for your brain and declines with age. Whether topping it up via NMN (a substance your body converts into NAD+) or other means actually helps has not yet been convincingly demonstrated in people. Wait for the results of larger studies in people before drawing firm conclusions.