The anti-aging boom is upon us. Peptides are popping, and people are ditching sweat-soaked HIIT sessions for workouts that support longevity. Meanwhile, familiar supplements like vitamin D and magnesium are making way for products that promise extended healthspan, like NAD—a multitasking molecule that experts claim can support DNA health while boosting everything from energy to skin health.

But what exactly is NAD, and is it worth your attention? At a time when looksmaxxing influencers are blasting retatrutide into their veins before clinical trials have even concluded, it’s become more important than ever to question not just the efficacy but also the safety of the supplements and drugs that pop up in our social media feeds.

Here’s everything the experts—and the results of published, peer-reviewed clinical trials—have to say about NAD.

What is NAD?

“NAD” is an acronym for nicotinamide adenine dinucleotide, a molecule that has multiple important functions. Emma Wedgwood, an advanced nurse practitioner, says that, at the top level, it “helps keep our cells functioning properly.”

“It plays an essential role in energy production by converting the food we eat into the fuel our cells need,” says Wedgwood. “NAD comes in two forms, NAD+ and NADH, both working together to ensure that our bodies have the energy they need to perform vital functions. Beyond energy, NAD also supports processes like DNA repair and immune health. As we get older, NAD+ levels tend to drop, which can affect our energy and cell regeneration, making it a focus in anti-aging and wellness research.”

This is why NAD is a popular health supplement for those over 30 and are starting to see their energy, metabolism and immune support decline.

Is there a difference between NAD+ and NADH?

You’ll likely have seen two options in NAD offerings: NAD+ and NADH. As to the difference between the two, Wedgwood says it’s all about the roles they play in the body.

“NAD+ helps create energy by turning food into fuel and supporting cell repair. It’s like the ‘starter’ for energy production,” says Wedgwood. “NADH, on the other hand, is the form that carries and delivers the energy where it’s needed in the body. Think of NAD+ as the builder of energy, and NADH as the transporter, ensuring cells get the power they need. Both work together to keep everything running smoothly.”

What are the benefits of NAD?

Because it’s a vital part of how your DNA works, NAD has a variety of different and useful functions in the body. A couple of the main ones are energy levels, metabolism support, skin health, immune system and DNA repair.

But how exactly does that all work? As Dr. Rishi Mandavia, managing director at Doctors Tatiana + Rishi Advanced Aesthetics, says it’s all about energy conversion. “NAD plays a big role in your metabolism, which is how your body turns food into energy. It helps with key processes that produce ATP [adenosine triphosphate], the energy your cells need to function. Without enough NAD, your body’s ability to create energy slows down, making it harder for your cells to do their jobs.”

NAD can also be an anti-aging boost as well. “NAD is linked to anti-aging because it helps repair cells, protect against damage and support healthy function in things like DNA repair and mitochondrial health,” says Mandavia. “Since NAD+ levels naturally decline as we age, keeping those levels higher might help slow some signs of aging—though more research is needed.”

There’s more: NAD can also have an effect on “managing stress, immune function and regulating your body’s internal clock, or circadian rhythms,” says Mandavia. “It also helps control how genes are expressed, which can impact overall health and longevity.”

Can you take a NAD supplement?

Here’s where it gets a tiny bit more complicated. NAD supplements can be delivered in both an oral form (usually as a tablet, but also a powder) as well as an intravenous or intramuscular injection. The benefits of correct supplement taking should include higher energy levels, boosted metabolism, better stress management and improved sleep, among other things.