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Can NAD+ Supplements Really Boost Longevity and Slow Aging?
Research is limited, experts say, and the supplements can cause side effects
6-minute read
Glenn Harvey
If you’ve spent any time on social media lately, you’ve likely seen influencers touting NAD+ supplements as a way to boost longevity and slow aging. But is there any evidence to support these claims?
Here’s what experts want you to know about NAD+ supplements, plus what the evidence shows about their potential risks and benefits.
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What is NAD+?
NAD+ stands for nicotinamide adenine dinucleotide; the plus sign indicates it’s oxidized. Found in cells throughout the body, it’s a coenzyme — or a molecule that assists in reactions — that helps with essential functions such as converting the food you eat into energy and repairing damaged cells. It also helps keep your heart, brain and muscles healthy.
Your body produces NAD+ naturally using building blocks like vitamin B3 and the amino acid tryptophan. Your cells can also recycle NAD+ from other molecules.
And while some animal studies have shown that NAD+ declines with age, this hasn’t been well documented in humans, says Andriy Yabluchanskiy, an associate professor at the University of Oklahoma College of Allied Health who researches NAD+.
One issue is that there’s not a standard way to measure NAD+ in the body, says Christopher Martens, director of the Delaware Center for Cognitive Aging Research at the University of Delaware. Some studies measure it using blood samples; others measure levels in tissue. And this matters because where you look might affect what you find.
For example, a 2026 study published in Nature Metabolism suggests that NAD+ levels in the blood don’t decline with age. However, other research has found that NAD+ levels may drop in certain tissue as you age.
It may also be that NAD+ itself doesn’t decline as you get older, but that you use more of it, which could lower your overall levels, Yabluchanskiy explains. This may be because you experience more cellular stress with age, and cell repair mechanisms falter because “we’re ramping up the activity of these enzymes,” Martens says.
Experts say research on whether supplements can replenish NAD+ or improve your health is limited.
NAD+ supplements are “definitely taking off well ahead of where the science is,” Martens says.
What are NAD+ supplements?
NAD+ supplements are available in a variety of forms — from pills and gels to intravenous infusions at wellness spas.
But here’s the catch: These supplements typically don’t contain NAD+, and that’s because the body has a difficult time absorbing it. NAD+ is a large molecule that doesn’t easily cross cell membranes to enter the bloodstream, Martens explains.
Instead, the supplements usually contain building blocks — also known as precursors — that your body converts to NAD+. Yabluchanskiy says the most common ones are nicotinamide riboside (NR), a form of vitamin B3, and nicotinamide mononucleotide (NMN), which is synthesized from B3. These substances can penetrate cells and change into NAD+.
Niacin, another form of B3, is often not included in NAD+ supplements because high doses can cause side effects like skin flushing or an upset stomach, says Jean Moon, a professor at the University of Minnesota College of Pharmacy.
Do NAD+ supplements offer any benefits?
There is evidence that consuming these NAD+ precursors will increase the amount of NAD+ in the blood, Martens says. “What we know less about is whether the boost in NAD that’s occurring in blood is actually getting to the tissues,” where it could make a difference in how your body works, he explains.
At this point, there’s “no human evidence that NAD can extend lifespan in humans,” Yabluchanskiy adds. Most studies on NAD+ supplementation have been short term and have involved animal subjects. Human studies often show mixed results, but research is ongoing.
NAD+ supplements may have greater potential to address specific health conditions than to address aging overall, Yabluchanskiy says. For instance, some human studies have found that NAD+ supplements may benefit those with peripheral arterial disease (PAD), a condition where the vessels that carry blood from the heart to the legs are narrowed or blocked.
One study published in Nature Communications in 2024, coauthored by Martens, found that the NAD+ precursor NR helped increase walking speed for people over 50 who have PAD. Research coauthored by Yabluchanskiy and published in 2025 in The Journal of Pharmacology and Experimental Therapeutics found that NR could improve blood flow to brain regions involved in memory in older adults with PAD, modestly improving cognition.
However, a different study led by Martens and published in Alzheimer’s & Dementia found that while NR raised blood NAD+ levels in people over 65 with mild cognitive impairment, it didn’t improve cognitive function, blood pressure or cerebral blood flow.
Some research has shown NAD+ supplements could benefit people with Parkinson’s disease. But a recent randomized clinical trial published in JAMA found that NAD+ precursors didn’t improve clinical outcomes for people with Parkinson’s who were 65 and older.
Separately, a 2021 study published in Science found that the NAD+ precursor NMN may improve insulin sensitivity in women in their 60s who are overweight or have obesity and have prediabetes.
Are NAD+ supplements safe?
NAD+ supplements are generally considered safe for most healthy people, Moon says. But it is important to note that they can cause side effects such as nausea, headache, diarrhea and muscle cramps and that they may not be safe for everyone.
For example, Yabluchanskiy suggests avoiding NAD+ supplements if you have cancer or a history of cancer. He explains that cancer cells are “energy-hungry,” and NAD+ could provide that energy and encourage their growth, though research is ongoing.
People with liver disease or who are pregnant or breastfeeding should also avoid NAD+ supplements, Moon adds.
Should you try them?
Before starting any supplement, it’s important to talk to your doctor first, especially if you have a chronic condition or take other medications, Yabluchanskiy says.
If you decide to take NAD+ supplements, he suggests not exceeding the product’s dosage guidelines.
Moon adds that supplements, including NAD+, are not regulated by the U.S. Food and Drug Administration for safety and effectiveness the way prescription and over-the-counter medications are. She suggests choosing products certified by third parties that verify their quality, such as the United States Pharmacopeia (USP). These organizations check to make sure what’s in the bottle matches what’s on the label.
And know that you don’t need supplements to support healthy NAD+ levels. Regular exercise and eating foods rich in vitamin B3, including poultry, fish, whole grains, nuts and seeds, can help you maintain healthy levels. So can managing common health issues like chronic inflammatory conditions, diabetes and high blood pressure — all of which can decrease NAD+.
Getting plenty of sleep also helps restore NAD+, Moon says. Additionally, she recommends avoiding alcohol and UV exposure, which can cause cellular stress and deplete NAD+.
If you decide to try NAD+ supplements, “set realistic expectations,” Yabluchanskiy says, and recognize that there’s limited evidence supporting their benefits. Martens says NAD+ supplements aren’t something he’d be “eager to jump on,” and they likely won’t be a “remarkable solution.”
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