Can NAD Supplements Slow Down Aging? Here’s What the Science Is Saying

There’s a growing interest in aging and ways to slow it down — and research is shining a spotlight on NAD (which stands for nicotinamide adenine dinucleotide). It’s a substance that plays a key role in many bodily processes, but its levels naturally decline with age. Can taking an NAD supplement fight the effects of aging? Maybe. Here we discuss benefits, risks, and details of taking NAD supplements.

What is NAD?

NAD is a compound naturally found in your body. It plays an important role in many different processes, including:

• Energy production

• Metabolism

• DNA repair

• Circadian rhythm

• Inflammation 

Your body makes NAD from: 

• Recycling NAD that has already been used

• Tryptophan, a molecule that’s used to build proteins

• Vitamin B3, also known as niacin

NAD levels naturally decline as you age. Scientists aren’t entirely sure why. They think it may be because our bodies are less efficient at using and making NAD. It could also be because our bodies use more NAD as we get older, since DNA damage and inflammation increase with age.

What are the benefits of NAD supplements?

Increased NAD levels may lead to certain health benefits, such as:

• Improved cognition

• Improved liver and pancreas function

• Enhanced blood flow

• Better muscle strength

• A stronger immune system

But this is based on what we know about NAD’s role in your body. In other words, we don’t yet know if taking NAD supplements will lead to these benefits. 

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If you’re young and healthy, your body probably already has all the NAD it needs. Extra NAD from supplements is less likely to have health benefits. But there’s some research on the benefits of NAD supplements for older people with age-related health conditions. Below, we describe in more detail what the research shows so far.

One thing to keep in mind is that most of these studies involve small groups of people. There’s also a lot of variation in the type and dose of NAD supplements tested. This makes it difficult to know how a supplement will impact your individual health. 

Diabetes

The risk of Type 2 diabetes increases with age. 

In people with prediabetes, one study of postmenopausal women found that NAD improved insulin sensitivity. But other studies — in people with increased weight — didn’t see an effect on insulin or blood sugar. 

Another study looked at the effect of NAD supplements in people who already had Type 2 diabetes. They saw an increase in insulin production with NAD supplementation. But there was no change in their blood sugar or hemoglobin A1C (HbA1C) levels. So, it’s hard to say if it made a difference.

Heart health 

Like Type 2 diabetes, heart disease risk increases as we get older. For most people, this is around the age of 65. 

Several studies suggest that NAD supplementation may be good for heart health. Research has shown it may:

• Reduce something called arterial stiffness in healthy adults (stiff arteries increase your risk of stroke and heart attack)

• Decrease blood pressure in healthy adults 

• Increase high-density lipoprotein (HDL), the “good” cholesterol, in postmenopausal women

• Reduce markers of inflammation in the blood of people with advanced heart failure

Parkinson’s disease

Two studies suggest that NAD supplementation may help people with Parkinson’s disease (PD).

The first study found that NAD has the potential to slow disease progression and increase quality of life in people with PD. The second showed that it decreased markers of inflammation in spinal fluid. This decrease in inflammation is thought to be protective, potentially slowing progression of PD and improving symptoms.

Fatty liver disease 

Non-alcohol fatty liver disease (NAFLD) is now called metabolic dysfunction-associated steatotic liver disease (MASLD). Both names are a mouthful. But in basic terms, the condition describes the accumulation of fat in your liver, often linked to things like high blood sugar, high cholesterol, and increased weight. This can lead to inflammation and scarring in your liver, which can eventually impact liver function.

Given NAD’s role in metabolism, researchers are interested in whether it can impact the risk or progression of fatty liver disease. This is an ongoing area of investigation. But so far, the available studies don’t strongly suggest that NAD supplementation helps people with NAFLD.

One study in people with fatty liver disease, higher weight, and prediabetes showed a mild improvement in liver fat with NAD supplements. But a similar study showed no difference in liver fat in men and women with excess weight.

In another study of people with fatty liver disease and diabetes, researchers saw improved cholesterol but no changes in liver health.

Can you raise your NAD levels naturally without supplements?

Yes, you can raise your NAD levels naturally without taking supplements. Some ways to do this include:

• Exercising regularly

• Getting a good night’s sleep

• Maintaining consistent mealtimes

• Eating a well-balanced diet with foods rich in tryptophan and niacin

Foods high in tryptophan or niacin include:

• Chicken or turkey breast

• Canned tuna

• Beef liver or ground beef

• Pork tenderloin

• Salmon

• Brown rice

• Peanuts

• Whole or 2% milk

• Oats

How do you take NAD?

Most experts agree that people younger than 40 years old don’t need to take NAD supplements. If you’re considering giving them a try, NAD supplements come in different forms. And this is where things can get confusing.

NAD supplements are essentially different forms of vitamin B3. As we explained earlier, your body turns vitamin B3 into NAD. Most “NAD supplements” are one of these versions of vitamin B3:

• Nicotinamide (also known as niacinamide or NAM)

• Nicotinamide riboside (NR)

• Nicotinamide mononucleotide (NMN)

These supplements also come in capsules, powders, and liquids. Because NAD supplements are still in the early phases of research, there isn’t clear guidance on what dosage people should take. They also don’t know how long people need to take it to see results.

Another option is to take a vitamin B3 supplement, also called niacin or nicotinic acid. 

The recommended daily amount of vitamin B3 (niacin or NA) for adults is 14 mg of niacin equivalents (NE). The upper daily limit of niacin from dietary supplements for adults is 35 mg NE. But keep in mind that most adults get more than enough niacin from their diet and don’t need a supplement.

What are the most common NAD supplement side effects?

The most common NAD supplement side effects include:

• Muscle aches

• Trouble sleeping

• Headaches

• Skin flushing

If you take 1,000 mg or more of niacin daily, it can lead to more extreme side effects, like:

• Extreme fatigue

• Low blood pressure

• Elevated blood sugar

• Nausea and stomach pain

• Vision problems

Taking niacin in the form of NAD or NAM has fewer side effects overall. But taking 500 mg to 3,000 mg or more daily can lead to:

• Diarrhea

• Bruising

• Bleeding

• Liver damage

Why trust our experts?

Written by:

Cherilyn Davis, MD

Cherilyn Davis, MD, is a board-certified pediatrician in NYC. She's held local and national roles at the American Medical Women's Association, including board member of the physician division and physician chair of social media.

Edited by:

Katie E. Golden, MD

Katie E. Golden, MD, is a board-certified emergency medicine physician and a medical editor at GoodRx.

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