You can increase NAD+ levels through a combination of precursor supplements, regular exercise, dietary choices, and fasting. NAD+ (nicotinamide adenine dinucleotide) is a molecule every cell in your body uses to produce energy, repair DNA, and regulate aging processes. It declines significantly as you get older, with human liver tissue showing roughly a 30% drop between people under 45 and those over 60, and skin samples declining by at least 50% over the course of adult aging.
That decline is what drives most people to search for ways to boost it. Here’s what actually works, ranked by the strength of evidence behind each approach.
NAD+ Precursor Supplements
Your body can’t absorb NAD+ directly from a pill. It’s too large a molecule. Instead, supplements provide smaller building blocks, called precursors, that your cells convert into NAD+. The three main precursors available as supplements are nicotinamide riboside (NR), nicotinamide mononucleotide (NMN), and plain niacin (vitamin B3). Each enters the NAD+ production pipeline at a slightly different point, but all end up at the same destination.
NR is the most studied in human trials. A dose of 1,000 mg twice daily has been shown to increase whole-blood NAD+ levels up to 2.7-fold after a single dose. It’s been confirmed as well-tolerated at up to 2 grams per day across multiple studies, with no flushing (the uncomfortable skin reddening common with regular niacin) and no serious side effects. An 8-week trial testing doses up to 1 gram in overweight and healthy adults confirmed it’s safe and absorbed well when taken orally.
NMN has gained popularity in recent years and had a rocky regulatory history. The FDA previously excluded NMN from the supplement market because it was being investigated as a drug, but in September 2025, the agency reversed that position. NMN is now permitted as a dietary supplement, though manufacturers must submit premarket safety notifications before selling it. Human trials have tested 250 mg per day for around 7 to 8 weeks. In terms of raising NAD+, both NR and NMN show promise, but no head-to-head human comparison has been published. Both precursors appear to partially break down into nicotinamide (a simpler form of vitamin B3) in the blood and liver before reaching other tissues, which means neither may have as clean a delivery path as marketing materials suggest.
Niacin, the oldest and cheapest option, also raises NAD+ effectively but commonly causes flushing at higher doses. It remains a viable choice for people who tolerate it.
Exercise Raises NAD+ Production Naturally
Exercise is one of the most reliable ways to boost your body’s own NAD+ manufacturing. The key mechanism involves an enzyme called NAMPT, which is the rate-limiting step in recycling NAD+ inside your cells. As you age, NAMPT levels in muscle tissue drop steadily. But exercise reverses that decline.
A 12-week aerobic training program (3 to 4 sessions per week at moderate intensity, totaling about 180 minutes weekly) increased NAMPT levels by 12% in younger adults and 28% in older adults. Resistance training three times per week for 12 weeks performed even slightly better, raising NAMPT by 25% in younger people and 30% in older people. Cardio fitness level was the single best predictor of NAMPT abundance in skeletal muscle, stronger even than age itself.
Interestingly, short high-intensity interval training (five 1-minute sprints with 90-second rest periods, three times per week for six weeks) did not change NAMPT levels in fat tissue. This suggests the benefit is specific to the muscles you’re actually training and may require sustained effort over a longer period. The takeaway: consistent moderate exercise, whether cardio or weights, is more effective for NAD+ than brief intense bursts.
Fasting and Calorie Restriction
During fasting, your NAD+ levels rise across multiple tissues, including muscle, liver, and fat. This increase activates a family of proteins called sirtuins, which play a central role in cellular repair, energy efficiency, and longevity. The connection between calorie restriction and sirtuins was first discovered in yeast, where lifespan extension from reduced calories required a functioning NAD+ production pathway. The same mechanism operates in mammals.
Calorie restriction doesn’t need to be extreme. The core principle is that your body ramps up NAD+ during periods of energy scarcity as a way to optimize cellular function under stress. Intermittent fasting likely taps into this same pathway, though most of the controlled data comes from sustained calorie restriction in animal models rather than time-restricted eating in humans. Still, the biology is consistent: metabolic stress from reduced food intake pushes NAD+ levels upward.
Foods That Provide NAD+ Precursors
Certain foods contain small amounts of NMN and NR naturally. Edamame has the highest measured NMN content at 0.47 to 1.88 mg per 100 grams, followed by avocado at 0.36 to 1.60 mg per 100 grams. Broccoli, cucumber, cabbage, and tomato contain smaller amounts. Raw meats and seafood provide 0.06 to 0.42 mg per 100 grams. Cow’s milk is the richest measured source of NR, and human breast milk contains the most NMN of any milk tested. Craft beers brewed with yeast also produce measurable NR and NMN during fermentation.
To put these numbers in perspective, you’d need to eat dozens of kilograms of edamame daily to match even a low-dose NMN supplement. Dietary sources contribute to your baseline NAD+ production but can’t replicate the concentrated boost of a supplement. More broadly, your body also makes NAD+ from tryptophan (found in turkey, eggs, cheese, and other protein-rich foods) and niacin (abundant in chicken, tuna, peanuts, and mushrooms). Eating enough protein and B vitamins supports the raw material supply your cells need.
IV NAD+ Therapy
IV infusions of NAD+ are marketed at wellness clinics, typically for anti-aging, addiction recovery, or energy enhancement. These infusions bypass the digestive system and deliver NAD+ directly into the bloodstream. However, published clinical evidence supporting IV NAD+ is thin. A systematic review of NAD supplementation across various clinical conditions found that studied protocols were overwhelmingly oral, not intravenous. The side effects reported across NAD supplementation studies (oral forms) included muscle pain in 24% of participants, nervous system complaints in 22%, fatigue in 20%, sleep disturbance in 20%, and headaches in 18%. Gastrointestinal issues, nausea, and skin rash occurred in smaller numbers.
IV sessions at clinics typically cost several hundred dollars each and are not covered by insurance. Without robust trial data on IV-specific dosing, safety, and effectiveness, it’s the least evidence-backed option on this list.
Combining Strategies for the Biggest Effect
These approaches are not mutually exclusive. Exercise increases the enzyme that recycles NAD+ in your cells. Precursor supplements provide more raw material to feed that recycling process. Fasting activates the downstream proteins that use NAD+ for repair and energy regulation. A practical combination might look like regular strength training or cardio several days a week, an NR or NMN supplement at a dose supported by trial data (250 to 1,000 mg daily depending on the precursor), adequate protein and B vitamin intake from food, and occasional periods of calorie restriction or time-restricted eating.
The decline of NAD+ with age is real and well-documented, with brain imaging studies showing a 10% to 25% drop between young adulthood and old age. But the tools to counteract that decline are accessible, and the strongest ones, exercise and nutrition, cost nothing.