NAD is the latest supplement having a moment on social media these days. TikTok users are posting about the supposed benefits of this so-called “miracle anti-aging pill” and are even selling bottles of the supplement to their viewers, promising that NAD will not only give them younger-looking skin but also more muscle tone, energy, and an overall youthful feeling. Even celebs like Kendall Jenner and Hailey Bieber are getting in on the NAD trend. The models are featured in a viral clip from The Kardashians, where the pair got at-home IV drip treatments filled with NAD. Bieber even jokes and says, “I’m gonna NAD for the rest of my life, and I’m never gonna age.”

But first, let’s start with the basics. What is NAD, and why are celebrities (and average social media users) obsessed with the supplement all of a sudden? Does it really help “reverse the aging process,” or is it just another overhyped supplement without scientific evidence to support its benefits?

We spoke with a longevity doctor and dietitian to learn more about NAD, plus whether or not the supplement form is actually worth a try based on evidence-based medical research.

Just a Note

Before trying any new vitamin or supplement, it’s best to talk to your doctor first to make sure it’s right for you. Certain supplements can negatively interact with prescription medications or may not be right for people with certain underlying health conditions.

What is NAD?

NAD, short for nicotinamide adenine dinucleotide, is a naturally occurring biomolecule found in all living cells. It’s essential for cellular processes like converting food into energy (a process known as cellular respiration), repairing DNA, and regulating immune system functioning. It’s mainly produced and stored in our cells’ mitochondria—the powerhouse of the cell.

As we get older, our NAD levels naturally decline, which research suggests¹ is one of the driving forces behind age-related muscle loss², cognitive decline, and insulin resistance³. Younger people may experience a drop in NAD levels, too, from things like “overtraining or over-exertion, COVID and long-COVID, various inflammatory conditions and illnesses, or general poor health,” Sajad Zalzala, MD, a longevity and preventive health expert and co-founder and medical director at AgelessRx, tells Well+Good.

This is why NAD is offered and sold in supplement form—as a way to boost NAD levels and offset the aging process where it begins: inside the cells.

NAD supplements come in several different forms, including pills, patches, powders, or intravenously (aka through an IV drip). There are also several subtypes of NAD, including NAD+ and NAD precursors such as nicotinic acid (NA), nicotinamide adenine dinucleotide hydrogen⁴ (NADH), niacinamide¹⁰⁵ (NAM), niacinamide mononucleotide⁶ (NMN), and nicotinamide ribose⁷ (NR). The difference between each subtype is mostly bioavailability, i.e., the ability for a substance to be absorbed by your body.

Research has found that NR and NMN appear to be most effective at raising NAD+ levels⁸; however, whether that translates into meaningful anti-aging effects remains to be seen.

Does it work for anti-aging?

“Research shows⁹ [NAD supplements] may support energy metabolism, reduce inflammation, enhance mitochondrial function, and promote healthy aging at the cellular level,” Vandana Sheth, a registered dietitian nutritionist specializing in plant-based diets and diabetes, tells Well+Good.

However, the research in question is relatively new and limited. Most of the studies on NAD supplements so far have been conducted on animals rather than humans and include very few participants. Ultimately, we need more robust human studies to confirm the supposed anti-aging benefits of NAD.

Here is what early research has to say:

1. May help protect skin

Niacinamide (also known as nicotinamide or vitamin B3) is a component of NAD that’s commonly used as an anti-aging ingredient in skincare products. Preliminary studies¹¹ suggest topical and oral niacinamide may help protect against UV damage and reduce inflammation, which contributes to skin aging. But early human studies suggest that only topical niacinamide¹² may help enhance skin elasticity, reduce wrinkling, and protect against skin dehydration.

Keep in mind: Oral niacinamide has not been widely investigated in humans for skin aging.

2. Might help prevent muscle loss

NAD decline has been proposed as one of the culprits for muscle loss, which begins in our 30s and accelerates in our 60s. Several studies have looked into the effects of NAD+ supplements on indicators of muscle health¹³, such as gait speed, grip strength¹⁴, the six-minute walking test, and the frequency of the 30-second chair-stand test. While most of these studies have yielded positive results, it’s worth noting that the sample and effect sizes are small.

This means taking NAD supplements resulted in small improvements in muscle function, but it didn’t necessarily increase mobility or independence into older adulthood. FWIW though, moderate exercise¹⁵ has also been shown to boost NAD+ levels and offset age-related muscle loss.

4. Can help support heart health

Early research¹⁶ indicates that taking supplements known as NAD+ precursors (i.e., NA, NMN, NAM, NR) can have a positive effect on risk factors for heart disease, including total cholesterol, triglycerides, LDL (“bad”) cholesterol, and HDL (“good”) cholesterol. (For context, high total and LDL cholesterol and high triglycerides lead to stiffness and a buildup of plaque on artery walls, while HDL cholesterol has the opposite effect on arteries.)

Because total cholesterol, LDL cholesterol, and triglycerides all tend to increase with age, NAD+ is thought to offset the rise in these numbers. But keep in mind: These findings are still new and need to be further studied to prove effective.

Other possible benefits of NAD supplements

Beyond the anti-aging properties and claims, there are a few other purported benefits of NAD supplements worth noting. Here is what the research has to say:

1. These supplements may help regulate blood sugar

NAD+ supplements have shown promise for blood sugar control in animal models¹⁷, but only a handful of small trials have investigated this in humans. One trial showed that NMN supplementation improves insulin sensitivity¹⁸ in post-menopausal people living with obesity. However, there’s not enough evidence to show that these results apply to other groups of people. Therefore, additional robust research is still needed to confirm these claims.

2. Some evidence suggests they can reduce COPD symptoms

A randomized, placebo-controlled trial found that NR supplementation may help reduce interleukin-8¹⁹—an element found in the blood that, when elevated, serves as a marker of chronic inflammation and chronic obstructive pulmonary disease (COPD) severity. COPD is a group of respiratory conditions that make it difficult to breathe, including emphysema and chronic bronchitis. The World Health Organization says it’s the fourth leading cause of death worldwide and is characterized by shortness of breath, wheezing, ongoing cough, and/or mucus production.

Just note that this study only involved 40 people, and again, more research is needed to prove its findings.

3. Early research shows some improvements in endurance

A small trial on 48 young and middle-aged runners who trained for 40 to 60 minutes, five to six times per week, showed that NMN supplementation improved aerobic capacity and endurance²⁰. In the study, NMN supplementation increased oxygen uptake and improved endurance as the exercise intensity increased. But again, this study is small and preliminary; more studies are needed to confirm its results across different age groups and athletes.

Another thing to note: NAD supplements are also currently being explored as an adjunct therapy²¹ for Alzheimer’s disease, Parkinson’s disease, obesity, chronic fatigue syndrome, non-alcoholic fatty liver disease, and ovarian aging and infertility, with several trials underway.

Risks and side effects of NAD

While the early results of NAD clinical trials are encouraging, there’s still a lot we don’t know about how these supplements affect the body, including their long-term side effects and risks. For this reason, it’s best to talk to your healthcare provider before trying NAD to weigh out the benefits and risks.

NAD supplements are generally safe and well-tolerated in the short term, but there are some possible side effects. Oral NAD²² supplements may cause bloating, muscle pain, itching, sweating, changes in bowel habits, dizziness, and headaches. Topical NAD can also cause side effects, including itching, burning, and redness.

“Not everyone will benefit from boosting NAD+ levels. Young people who are in very good health likely have plenty of NAD already, and adding more is likely to be of little benefit,” says Dr. Zalzala.

NAD is not heavily regulated by the FDA

It’s important to keep in mind that supplements (like NAD) are not regulated in the same way drugs are by the U.S. Food and Drug Administration (FDA). While supplements are loosely regulated by the FDA, they still cannot claim to treat, cure, or prevent any disease. Ultimately, it is up to the manufacturers to uphold these guidelines, but sometimes, this means the claims and ingredient amounts printed on supplement labels do not accurately reflect what’s inside the product itself. This is why it’s best to purchase supplements that have been third-party tested by reputable companies like The United States Pharmacopeial Convention or NSF.

Because of this discrepancy, NMN is currently banned by the FDA from being sold as a supplement because it’s being investigated as a drug. NMN is currently in the murky space between drug and supplement and cannot be sold as either for the time being.

The bottom line

While early human clinical trials of NAD supplements have been encouraging, there is still not enough research to confidently say NAD supplements will “reverse aging.” It’s also unclear whether NAD supplements can have a significant positive effect on your overall health.

So, do you need them? Likely, no (despite what celebs and TikTokers may tell you). But if you’re still curious to try them, talk to your healthcare provider to determine the right dose, form, and type of NAD supplement that are best suited for your needs.