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WellnessChecked Editorial · October 2026
NAD+ Supplement Guide — What It Is and How to Raise It
What NAD+ is, why levels are thought to fall with age, and what small human trials of NMN and NR actually show about raising it, plus safety and what remains unproven.
⚡ Quick AnswerLast Reviewed: October 2026
NAD+ (nicotinamide adenine dinucleotide) is a coenzyme every cell uses for energy metabolism and for enzymes involved in DNA repair and cell signaling. Levels appear to fall with age in animals and some human tissues. NMN and NR, two forms of vitamin B3, reliably raise NAD+ in blood in small, short human trials, but benefits beyond that are limited and mixed, and neither has been shown to slow aging.
What Is NAD+?
NAD+ is a coenzyme found in every living cell. It shuttles electrons in the reactions that turn food into usable energy (ATP), and it is used up by enzymes such as PARPs, which help repair DNA, and sirtuins, which help regulate metabolism and stress responses.
Why NAD+ May Decline With Age
Animal studies and some human tissue studies suggest NAD+ levels fall with age. Proposed reasons include lower activity of NAMPT, a key enzyme for recycling NAD+, and higher use of NAD+ by enzymes such as CD38 and PARPs. How large the decline is in people, and how much it matters for health, is still being worked out.
Supplements That Raise NAD+
NMN (nicotinamide mononucleotide): a handful of small (about 10 to 110 people), short (2 to 12 week) placebo-controlled trials at 250 to 1,250 mg a day show it reliably raises blood NAD+. A few reported modest changes in muscle insulin sensitivity, walking distance or grip strength, but results are mixed and several trials were funded by NMN makers. The FDA said in September 2025 that NMN can be sold as a dietary supplement.
NR (nicotinamide riboside): has more published human research. A 2023 review of 25 human studies found NR reliably raised NAD+ in blood but showed no sign of raising it in muscle, and clinically meaningful benefits were few.
Resveratrol: not an NAD+ precursor. It was promoted as a sirtuin activator, but whether it directly activates SIRT1 in the body is debated, and human trials show small, inconsistent effects.
Exercise: a reasonable habit for many reasons; its effect on NAD+ in people is still being studied.
No published trial has shown NMN to be better than NR, or the other way round, at raising NAD+ in people, and none shows that either slows aging.
In published trials, NMN has been well tolerated at 250 to 2,000 mg a day and NR at up to 1,000 mg a day, but the studies were small and short, so long-term safety is unknown. People who are pregnant, being treated for cancer, or taking diabetes or blood pressure medicines should talk to their doctor first. GenuinePurity Liposomal NMN, our top pick among NMN supplements, provides 500 mg of NMN per 2-capsule serving; the product itself has not been tested in a trial.
NAD+ (nicotinamide adenine dinucleotide) is a coenzyme in every cell, needed for energy metabolism and used by enzymes involved in DNA repair (PARPs) and metabolic regulation (sirtuins).
Animal and some human tissue studies suggest NAD+ falls with age, possibly because of less recycling by the enzyme NAMPT and more use by enzymes such as CD38 and PARPs. How much it declines in people is still being studied.
NMN and NR both reliably raise blood NAD+ in small human trials. NR has more published research. Neither has been shown to improve health or slow aging in people beyond raising NAD+ levels.
No published trial has compared them head to head in people. They are different molecules, so comparing milligrams isn't very useful.
Diet and exercise support overall metabolic health, and research on their effects on NAD+ in people is ongoing. Supplements raise blood NAD+, but whether that improves health is not yet known.
Disclaimer: For informational purposes only. Dietary supplements — not medicines. Not intended to diagnose, treat, cure or prevent any disease. FDA not evaluated. Individual results vary. Consult healthcare professional. Affiliate commissions may be earned. We only cover products from brands we have affiliate relationships with, so our top picks are the best of the products we cover, not of every product on the market. Full disclaimer →
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