Experts Reveal If It Works for Anti-Aging & More

Everyone is talking about NAD, the latest trendy supplement touted for anti-aging and other health benefits. It’s all over TikTok, where proponents claim that taking supplements of NAD or NAD-boosting compounds can slow or even reverse aging, which may improve metabolism, cognition or even skin health.

Hailed by many as a “fountain of youth,” supplementing with NAD has become a popular biohacking regimen among wellness influencers and celebrities. Many swear by NAD pills or injections to feel and look younger, for as long as possible.

Many NAD supplements come in sleek, futuristic packaging — and at a high price — which stands out among the mainstays in the drugstore supplement aisle.

As with many over-the-counter remedies, the host of benefits almost sounds too good to be true. Are NAD supplements really the future of anti-aging?

All promising claims on labels and social media endorsements aside, the science behind NAD supplementation is a lot more complicated.

Research on NAD is ongoing, which means we’re still learning about this coenzyme and its potential uses. Additionally, there are several different types of NAD-boosting supplements you can take, all with similar-sounding acronyms for names: NAD+, NADH, NR, NMN.

What’s the difference between the various NAD supplements, and do they actually work? Can NAD actually combat aging and turn back time, or is it just hype? TODAY.com spoke with experts explain what NAD does in the body, how NAD supplements work, and what the science says about potential benefits and risks.

What is NAD?

NAD, also known as nicotinamide-adenine dinucleotide, is a coenzyme found naturally in the cells of the body, which plays an important role in energy production and other processes, Dr. Amanda Kahn, a board-certified internist and longevity medicine specialist based in New York City, tells TODAY.com.

A coenzyme is a helper molecule that binds to an enzyme to help carry out a chemical reaction. NAD assists in processes in the mitochondria, the powerhouse of the cell, and helps “keep the gears running” in the reaction that makes ATP, or cellular energy, says Kahn.

“NAD is a really critical molecule involved in metabolism … (and) making energy, which is needed for every function of the body,” Christopher Martens, Ph.D., associate professor of kinesiology and applied physiology at the University of Delaware, tells TODAY.com.

What does NAD do in the body?

NAD helps hundreds of enzymes in our cells do their jobs, from energy production to mitochondrial function. “Some of those enzymes are involved in cellular repair, so helping cells that have damage due to ultraviolet (UV) radiation, for example,” says Martens.

NAD also plays a crucial role in DNA repair, inflammation, cellular signaling, circadian rhythm and more.

“It’s in all our cells, helping make energy but also helping repair ourselves,” says Martens. Therefore, NAD is important for the healthy aging of tissues throughout the body.

Our NAD stores start to decline around young adulthood and keep declining as we age, Kahn notes.

“Part of that is thought to be due to the fact that we accumulate more damage over our lifespan. So all these enzymes are more active, trying to repair the damage and consuming more of the available NAD,” says Martens.

The total amount of NAD in our cells also decreases with cardiometabolic diseases, studies suggest.

The thought is that NAD supplementation can replenish these stores, but there’s more than one way to do this.

NAD+ vs. NADH

NAD+ or NADH are both are forms of the NAD molecule. NAD+ is the positively charged form, which means it has lost an electron. NADH is the neutral form of NAD, which has gained an electron.

NAD+ and NADH work together to transfer electrons back and forth to facilitate energy production and other reactions, says Martens.

NAD supplementation may involve taking NAD+ and NADH, or other compounds that the body converts to NAD on its own. These are all intended to raise NAD stores in the body, Kahn notes.

NR vs. NMN

Nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN) are both forms of vitamin B3 (niacin), which act as precursors to NAD+ in the body, the experts explain.

“You can take these, the building blocks to make your own NAD, (instead of) taking NAD itself,” says Kahn.

This is because NAD is broken down in the body into these molecules (NR and NMN), which can be converted back into NAD through a recycling pathway in the body, says Martens.

The main difference is NMN is one step closer than NR to being converted into NAD.

The body also converts niacin and the amino acid tryptophan into NAD, says Martens — these are found in some foods and available as supplements, but may not be as effective.

NAD supplements may contain one or more forms of NAD and its precursors. Always read labels closely.

Which type of NAD supplements are best to take?

“When you take NAD itself, we’ve found those supplements are not very bioavailable, meaning you don’t absorb as much as we would need to boost your levels,” says Kahn.

The two most popular NAD precursors, NR or NMN, are more stable and available, especially as oral supplements, says Martens. “NAD itself is not as stable, so it’s not quite as efficient to take a pill that contains just NAD,” says Martens.

“It’s easier to get into the bloodstream if we take in one of those precursor forms, and the hope is that our cells will know what to do with it and convert it back to NAD,” says Martens.

(In 2022, the U.S. Food and Drug Administration banned the sale of NMN as a dietary supplement because the ingredients are under investigation as a new drug.)

NAD supplement forms

You can find NAD supplements in capsule, powder and liquid form. These may be taken or administered in the following ways:

• Orally
• Nasal spray
• Injection
• Intravenously

Oral NAD supplements (NAD+, NADH, NR or NMN) are the most popular, the experts say.

NAD shots are injected subcutaneously, or under the skin, and enter the bloodstream more quickly because they bypass the digestive system, Kahn adds. These can be self-injected at home.

NAD-boosting supplements can also be diluted in a saline solution and administered through an intravenous (IV) drip, directly into the bloodstream, which should only be done by a health professional.

NAD supplement dosage

There is no established recommended dosage for NAD supplements. Dosing varies depending on the type and form. Oral NAD supplements usually start around 100–250 milligrams, which may be taken multiple times per day.

“I am not a proponent of IV therapy because I think you can get too much at once,” says Kahn, adding that she prefers dividing supplements into smaller doses given over a longer period.

Consult with your doctor to determine which dosage and frequency is best for you, says Kahn.

Supplements are regulated by the FDA as foods, not drugs, and the labels are not approved before the products go to consumers. Further, dietary supplements are not intended to prevent, treat or cure disease.

NAD supplement benefits

Aging and many chronic diseases are associated with lower NAD+ levels, the experts note, and there is ongoing research into the effects of NAD supplementation and potential benefits.

However, evidence from human studies is limited due to small sample sizes, researchers found in a 2023 literature review.

Preclinical studies in rodents have suggested that NAD-boosting supplements may help:

• Delay signs of aging
• Boost metabolism
• Improve insulin resistance
• Promote cognition
• Protect heart health
• Improve fertility
• Fight gut inflammation

While the results of some animal studies are encouraging, there is limited clinical data demonstrating that NAD supplementation is effective in humans.

In a 2018 study published in Nature, healthy adults were given NR supplements for six weeks as part of a randomized controlled trial. “It was really the first time NR had been given chronically over several weeks to humans,” says Martens, who co-led the study.

The results showed that NR supplements effectively increased concentrations of NAD+ in the blood. “We know in both animals and humans, if we ingest these precursors, the amount of NAD in blood goes up dramatically,” says Martens. Recent research shows these precursors can also increase NAD+ levels in multiple tissues.

“What we don’t know is whether that increase in NAD is having a real, meaningful effect on the function of our cells, and from there, the function of our organ systems and health outcomes,” he adds.

Early research suggests NAD-boosting compounds are promising, but more high-quality studies are needed among both healthy individuals and populations with risk factors associated with lower NAD levels, the experts say.

“Some trials are starting to look at groups of people that may be more vulnerable to chronic disease, and who knows, maybe that’s where we’ll see a bigger impact,” says Martens.

Can NAD supplements reverse aging?

“The NAD stores drop with age, so that’s a very obvious target in terms of slowing down or even reversing the aging process by giving it back to you,” says Kahn.

While animal studies suggest NAD supplementation may help delay signs of aging, more clinical trials among humans are needed to draw conclusions about anti-aging benefits.

“We’re really still in the early phases of trying to figure out if this stuff is going to have a benefit or not,” says Martens.

NAD side effects

NAD supplements are generally safe for most people when taken at the dosage recommended by a doctor, experts note.

In a 2023 review researchers found that supplementation with NAD-boosting compounds was safe and tolerable in healthy, middle-aged and older adults. However, safety data is limited, and there isn’t evidence that NAD supplements are safe for pregnant people.

If you have any underlying conditions, talk to your doctor before trying NAD, says Kahn.

There is a risk of mild side effects, especially with high doses. These include stomach upset, headache or skin flushing. NAD injections may cause temporary redness or pain at the injection site, says Kahn.

“For most people, the risks are very low because we’re already making (NAD) in our body,” she says.

However, Kahn warns that NAD IV therapy presents more risks. IVs are considered safe when administered by a qualified health care professional, but there’s always a chance of infection. “It really depends on who’s doing the IV. … A lot of people have a person come over to do it or go to med spas, which are less regulated,” Kahn adds.

If you experience side effects after taking NAD supplements, stop use and contact your doctor.

How long does it take for NAD to start working?

“You can boost NAD relatively quickly with one dose or two, but that’s blood NAD (levels). Whether that’s actually getting into the body (and tissues) is a bigger question,” says Martens.

NAD IV therapy and injections tend to work faster compared to pills. However, it’s unclear whether one is more effective than another.

The dosing regimen of NAD supplements in studies varies, and more research is needed to determine the optimal duration.

Can you boost NAD naturally?

It may be possible to increase or maintain NAD levels naturally. “If you’re living a healthy lifestyle, then you’re at least preserving the NAD that you have and allowing those cellular pathways to do their job of recreating the NAD,” says Martens.

It’s important to avoid habits that can put the cells in metabolic stress and use up more NAD for repair, says Martens.

You may be able to increase or preserve NAD levels by:

• Eating a healthy diet
• Exercising regularly
• Getting adequate sleep
• Avoiding UV radiation
• Limiting or avoiding alcohol
• Avoiding smoking

In addition to a living a healthy lifestyle, it’s important to get regular checkups and screenings, the experts say.