What You Should Know About NAD+ Supplements

Nicotinamide adenine dinucleotide, or NAD+, has become one of the most talked-about supplements in the longevity space. TIME magazine profiled it in 2018 as an anti-aging pill on the horizon, and it's been featured prominently in the scientific search for youth.

But if you strip away the marketing hype about NAD+ IV infusions and supplements and examine what the science actually reveals, the answer is both more complex—and more cautious—than enthusiastic headlines suggest.

The science

NAD+ (nicotinamide adenine dinucleotide) is a molecule that exists in every living cell in your body. Think of it as a cellular currency that helps convert the food you eat into energy your cells can use. It's also essential for DNA repair and other cellular maintenance processes that help keep your body functioning properly.

The challenge is that NAD+ levels naturally decline as we age, leading scientists to wonder whether this drop contributes to aging and age-related diseases—and if supplementing with NAD+ could help mitigate those drops.

To counter this age-related decline, researchers have developed so-called NAD+ boosters—compounds that raise NAD+ levels. The most studied are nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN), both derivatives of vitamin B3 that act as precursors to NAD+.

The potential benefits

In lab studies, NAD+ precursors like NR and NMN can increase NAD+ levels by 40-90% in the short term with minimal side effects. Animal research has shown some promising effects, including improved insulin sensitivity and better cardiovascular and brain health—benefits that mirror some effects of exercise or calorie restriction.

However, the lifespan extension results have been more mixed. While some early animal studies suggested modest life extension, more recent and rigorous research tells a different story. A 2025 study found no difference in lifespan compared to placebo, and the National Institute on Aging's Interventions Testing Program—considered the gold standard for aging research—found that NR supplementation didn't extend lifespan in mice.

In humans, the evidence is even more preliminary. More than 70 published studies suggest that NAD+ supplements are generally well-tolerated, with typical side effects including nausea, fatigue, headache, or flushing. Some early research hints at benefits for insulin sensitivity and blood pressure, but these findings need much more study before we can draw firm conclusions.

Despite evidence that elevating NAD+ through supplementation is possible, it remains unproven whether this translates to slower aging or disease prevention in people.

Concerns about long-term safety

Despite the generally good safety profile, experts urge caution, especially for long-term use. NAD+ is involved in countless cellular processes, and chronically altering its levels could have unintended consequences. One area of particular concern is cancer.

The relationship between NAD+ and cancer is complex. On one hand, maintaining adequate NAD+ levels helps cells repair DNA damage, which could theoretically protect against the mutations that lead to cancer. On the other hand, cancer cells have high energy demands and are greedy for NAD+ to fuel their rapid growth.

A recent animal study raised concerns by showing that high doses of NR in mice appeared to increase the risk of aggressive triple-negative breast cancer and its spread to the brain. This finding suggests that in certain cancer-prone situations, extra NAD+ might inadvertently feed tumors.

While no direct evidence has shown NAD+ supplements cause cancer in humans, until more is known, people with active cancer or at high risk should avoid NAD+ boosters.

Regulatory uncertainty

Adding to the uncertainty, the regulatory status of NAD+ supplements remains in flux. In 2022, the U.S. Food and Drug Administration (FDA) ruled that nicotinamide mononucleotide (NMN) could not be marketed as a dietary supplement because it had been investigated as a drug first — a status that disqualifies ingredients from supplement use under federal law. In response, major retailers and platforms such as Amazon, PayPal, and Shopify began restricting the sale of NMN. Industry groups have pushed back against the FDA's decision, and legal and regulatory challenges are ongoing.

The bottom line

NAD+ supplementation represents a biologically plausible approach to addressing age-related cellular decline, and current evidence suggests it's safe in the short term. That said, based on the data, our key takeaways are:

The evidence is limited: While NAD+ supplements can raise NAD+ levels, there's no proof this translates to improved longevity or health status in humans.

Safety questions remain: Long-term effects are unknown, and long-term safety questions—particularly regarding cancer risk—are not yet settled.

As ongoing Phase II and III clinical trials continue to investigate NAD+ supplements, the smart approach is to remain cautiously optimistic while waiting for more definitive evidence. For now, the proven strategies for healthy aging—rather than a buzzy new supplement—remain your best bet for maintaining cellular health as you age.

This article is part of Atria’s Future of Health newsletter. Subscribe here.