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The growing interest in NMN aligns with a broader cultural shift in how people are thinking about aging. Registered Dietitian Avery Zenker points out that “longevity science isn’t only focused on increasing lifespan, but also improving healthspan.” Healthspan, in short, refers to living better as you age, not just living longer. According to Zenker, “NMN stands out for its potential to impact both lifespan and healthspan.”

So, what exactly is NMN, and why is it being promoted by so many wellness influencers? In this article, we look at how NMN works in your body, and we break down the claims around this popular wellness supplement.

What is NMN?

Naturally found in the body, NMN converts directly to NAD+, a compound essential for good health. An increase in NAD+ is associated with increased energy production and faster cellular repair.

Emerging research shows that NAD+ levels decrease greatly in middle age. According to Rachel Pojednic, PhD, Chief Science Officer at RestoreLabs and Restore Hyper Wellness, the popularity of NMN supplements is based on the idea “that by supplementing with NMN, you can increase NAD+ availability and potentially support cellular processes that are associated with healthy aging.”

How do NMN supplements work?

Pojednic explains it this way: an NAD+ boosting supplement like NMN is not like a direct infusion of NAD+ to your body. Rather, the supplements provide essential building blocks (called precursors) that help your cells make NAD+ on their own.

“NAD+ does not occur in high concentrations in the blood,” Pojednic explains, “and in fact, that would be an indicator to the immune system that something was wrong.” By using a precursor, like an NMN supplement, your body can produce NAD+ where it’s needed—inside your cells—without setting off any alarms within your immune system.

Although studies have shown that NMN supplements can increase NAD+ concentration, there are limited studies linking these increased NAD+ levels to changes in body composition or disease risk.

What experts say about NMN supplements

In 2022, the Food and Drug Administration (FDA) restricted the sale of NMN supplements because they were being investigated as pharmaceutical drugs. This decision was about regulatory classifications, not safety, but it has resulted in fewer human trials on the supplements over the past several years. In 2025, the ban on NMN supplements was lifted, and the supplement is finding its way back to the market and, potentially, to more clinical trials.

What’s clear from current studies is that NMN supplements increase NAD+ concentrations, with clinical trials showing “increases in whole blood NAD+ or related metabolites after NMN supplementation, which tells us the compound is biologically active and reaching its target,” Pojednic says. Such studies could point toward promising health outcomes, such as reduced inflammation and increased energy production.

Still, Pojednic says, “translating that into healthy aging in humans is where the evidence becomes much less clear.”

Benefits of taking NMN

While human trials on NMN supplements are limited, there is some promising research showing potential benefits, particularly insulin sensitivity, cardiovascular health, and metabolic health.

Here are some of the potential benefits of taking NMN supplements:

Increased levels of NAD+

Chronic, low-grade inflammation associated with aging (known popularly as “inflammaging”) gradually depletes NAD+ levels. NMN supplements provide a precursor that can help replenish these declining levels and support cellular health over time.

Protection against cancer and other chronic illnesses

Increased NAD+ levels can reduce inflammation throughout the body, potentially helping protect cells from DNA damage and oxidative stress, both of which are associated with cancer and neurological diseases like Alzheimer’s.

Support for metabolic health

One study found that NMN improved insulin sensitivity, a key marker of metabolic health, in the muscles of postmenopausal women with prediabetes and obesity. No data shows whether or not this finding translates to other populations.

Increased energy production

NMN supplementation resulted in increased NAD+ levels and an increased walking speed in older adults, one study showed. Additionally, participants reported better sleep quality, hinting at supportive effects on recovery and daily energy.

Improved brain health

In non-human studies, NMN supplements have been shown to improve cognitive function and reduce brain plaques associated with Alzheimer’s.

While these studies show exciting potential benefits of NMN supplements, more research is needed to show the long-term health benefits of NMN in the general population.

NMN’s potential side effects

In healthy people, a 1250 mg daily dose appears to be safe and well-tolerated for short-term use. “There’s a lack of safety data on other populations,” though, says Zenker, “like pregnant or breastfeeding women, children and adolescents, individuals with pre-existing health conditions, and those taking medications that could interfere with NAD+ and NMN processing.”

“Most human trials are relatively short, weeks to a few months, so we simply do not have robust long-term safety data,” Pojednic adds.

Anyone considering an NMN supplement, especially for long-term or high-dose use, should proceed with caution and be sure to consult with your doctor.

How to take NMN supplements

As NMN supplements have gained popularity, they’ve taken several forms, from IV infusions to capsules. Here are a few common NMN supplement forms:

• Powder
• Capsule
• Sublingual tablets (dissolve under the tongue)
• Nasal/oral sprays
• IV infusion

Registered Dietitian Jane Leverich points out that oral NMN supplements in powder or capsule form are the most commonly studied and have been shown to safely increase NAD+ levels in appropriate doses. “Though other delivery methods may be marketed as more effective,” she says, “there isn’t enough strong evidence to support their safety or that they offer additional benefits.”

Trace levels of NMN are also found in certain vegetables and lean meats, like broccoli, avocado, and beef, but the quantities are low and not likely to greatly impact NAD+ levels. “Rather than focusing on getting NMN directly through the diet, it’s more realistic to support NAD+ production overall through a balanced diet rich in protein that provides key nutrients like niacin and tryptophan, which help produce NAD+,” Leverich says. In other words, aim to increase your intake of niacin (vitamin B3) from foods like salmon, liver, and tuna. Other sources include legumes and fortified grains.

Do NMN supplements work?

At doses of 250 to 2000 mg daily, there is strong evidence to show that NMN supplements increase NAD+ levels in the blood and tissues. NAD+ plays a critical role in cellular energy production, DNA repair, and metabolic health. Your cells need it to survive and help you stay healthy and active. Because NAD+ levels decrease as we age, NMN supplements have grown popular as a tool for supporting longevity and overall health.

While preliminary findings are promising, there is limited clinical evidence in humans to confirm that increasing NAD+ through NMN supplements consistently leads to optimal long-term health or anti-aging outcomes. More large-scale and long-term studies are needed to determine the real-world impact of NMN supplements.

“For now,” Leverich says, “focusing on proven lifestyle habits like a nutrient-rich diet, staying physically active, prioritizing sleep, and managing stress remains the most reliable approach for increasing NAD+ levels.”

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