NAD+

What it is

NAD+ (nicotinamide adenine dinucleotide) is a coenzyme found in every cell, central to energy metabolism, DNA repair, and sirtuin signaling. It is not a peptide, but it is marketed in the same longevity market — as oral precursors (NMN, nicotinamide mononucleotide; NR, nicotinamide riboside; and niacin) and as IV or injectable preparations at wellness clinics.S3

Marketed as

NAD+ is marketed as an "anti-aging" and "cellular energy" product — through NMN / NR supplements and IV drips — for longevity, energy, recovery, and "reversing aging." Raising NAD+ is real; the anti-aging / longevity marketing outruns the human evidence (below).S3

Regulatory status (US)

Oral NAD+ precursors are sold as dietary supplements. FDA's position on NMN swung sharply: in November 2022 it declared NMN excluded from the dietary-supplement definition (because it had first been investigated as a drug), then in two letters dated September 29, 2025 it reversed that, concluding NMN was marketed as a supplement before that drug investigation and so is not excluded.S1S2 NMN remains a New Dietary Ingredient, so marketers must still file NDI notifications.S2 NR has been marketed as a supplement throughout. IV / injectable NAD+ is not an FDA-approved drug for anti-aging or wellness, and there are no accepted clinical guidelines for "wellness NAD therapy".S4

Around the world

NAD+ precursors are regulated very differently by region. In the US, oral NMN and NR are lawful supplements (after the 2025 FDA reversal); the UK permits NMN widely (FSA-monitored); but the EU classifies NMN as a novel food that is not yet authorized, so it can't be sold there as a supplement pending EFSA review.S6 IV NAD+ is a non-approved clinic product regardless of country.S4

Evidence

What precursors reliably do is raise blood NAD+ levels — human trials show NR and NMN increase NAD+ over supplementation.S3 There is a modest metabolic signal (for example, improved muscle insulin sensitivity in a trial of prediabetic participants).S3 But direct anti-aging or longevity benefit in humans is not established — much of that rests on animal work — and for IV NAD+ specifically there are no rigorous randomized trials for anti-aging, with contested bioavailability versus oral precursors.S3S4

Safety

Oral NMN and NR appear well tolerated short-term, but long-term human safety data are lacking.S3 IV NAD+ infusions commonly cause flushing and nausea during administration, and lack standardized protocols or long-term safety evidence.S4

Anti-doping

NAD+, NMN, and NR are not currently named on the WADA Prohibited List.S5 They are metabolic coenzymes and precursors, not peptide hormones or growth factors.

What's changing

The near-term items to watch are FDA's continued handling of NMN and other precursors as supplements, and whether the IV NAD+ clinic market draws regulatory attention given the gap between its marketing and the evidence.S1S4