At what age does taking NAD+ supplements make sense?
There is no established age at which NAD+ supplementation becomes worthwhile. Studies focus on middle-aged and older adults, but a measurable functional benefit in humans has not yet been demonstrated.
NAD+ supplementation has no established starting age. Studies have been conducted almost exclusively in middle-aged and older adults, and in people with cardiometabolic risk factors such as being overweight or having elevated blood sugar. A specific threshold age has never been investigated.
The most robust finding from human studies is this: when you take a capsule or tablet containing NMN (nicotinamide mononucleotide) or NR (nicotinamide riboside), your NAD+ levels in blood and tissues rise measurably. Which of the two you take does not matter: both raise NAD+ levels to a comparable degree. On the label, look for the amount of NMN or NR in milligrams per capsule or tablet. If you want to try it, the most commonly used approach is 300 to 600 mg NMN per day, or 1000 mg NR per day, for at least 8 to 12 weeks. Both substances are well tolerated; serious side effects have not been reported in the studies conducted. Note: NMN may not (yet) be sold as a supplement in the EU, whereas NR may.
The crucial question is whether higher NAD+ levels also lead to something you notice or can measure: better muscle strength, sharper memory or a healthier heart. Clear evidence for this in humans does not yet exist. The available studies are small, use varying doses and were too short to draw firm conclusions. NAD+ supplementation for life extension or general anti-ageing is too poorly studied to recommend: there is no evidence that any dose actually slows human ageing.
In mouse studies the results are more promising. In mice with Alzheimer pathology, NR reduced inflammatory responses, DNA damage and senescent cells, and also improved cognitive function. In other animal models, NAD+ supplementation improved heart failure and arterial calcification. These are animal models, however, and translation to humans has not yet been demonstrated.
If you are younger than forty and in good health, you have little basis to expect that supplementation will achieve anything: younger, healthy adults have barely been studied and their NAD+ levels have presumably not yet declined substantially. For short-term use in middle-aged and older adults, safety is reasonably well documented. Almost nothing is known about long-term use in younger people.
Claims based on reviews and small human trials (PMID 37068054, 41083806, 37619764) plus animal studies (PMID 34497121, 34843394) and one older review (PMID 26785480). No large RCT available. No study establishes a threshold age.
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.
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.
What are the effects of taking NAD every day?
Daily NAD supplements reliably raise your blood levels. The clearest signal comes from a form of NAD used in chronic fatigue research, though it comes from small studies.
What is NAD+ and why does it decline as you age?
NAD+ measurably declines with ageing, and supplements raise levels demonstrably in people. Whether that also makes you healthier has not yet been proven, and the safety of taking them for many years deserves attention.
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.