What Are NAD+ and NMN? Do They Work for Anti-Aging?

Understanding NAD and NMN

Before we discuss if and how NAD+ and NMN work for anti-aging, we should understand more about what these compounds do.

What Is NAD?

NAD exists in two forms — the oxidized state of NAD is known as NAD+, while the reduced state of NAD is known as NADH. Your cells maintain a delicate balance of NAD+ and NADH.

NAD+ is a naturally occurring substance in your body that’s necessary for more than 500 reactions, including:

Many of the reactions NAD+ is involved in regulate your response to oxidative stress. Free radicals are the main cause of oxidative stress. Free radicals are created during natural biological processes or in response to stress, such as toxins, ultraviolet (UV) exposure, or radiation. Free radicals can cause tissue damage and are one of the driving forces behind aging.

Your body makes NAD+ from other substances, known as precursors or NAD boosters, including:

What Is NMN?

NMN is a substance that’s converted to NAD+ in your body through a series of reactions. Your body can also make NMN from vitamin B3.

NMN is found in small amounts in several fruits and vegetables, including:

Understanding Aging

Aging is an inevitable and irreversible physiological process. While the average life expectancy of humans has increased in recent years, the maximum life span has not increased.

At a basic level, you age as a result of an accumulation of damage to your body over time. The damage gradually impacts your mental and physical abilities and increases your risk of disease. A few examples of physiologic changes that occur during aging include:

Aging is a major risk factor for several diseases, such as cancer, diabetes, heart disease, osteoporosis, and dementia.

If you scroll through the reactions NAD+ is involved in, you can see how NAD+ may be important to the aging process. For example, aging is associated with DNA damage, while NAD+ is involved in DNA repair. NAD+ is also involved in hormone signaling, which is an important part of how cells communicate in your body.

How Do NAD+ Levels Change As You Age?

NAD+ levels naturally decrease as we age. In fact, by the time you hit middle age (age 44 -64), your NAD+ levels are about half what they were when you were young.

One reason for lower NAD+ in older age is that your body makes less NAD+. At the same time your body is making less NAD+, it’s also using more of it to assist in processes such as repairing your DNA and responding to oxidative stress and inflammation.

Just like NAD+, your levels of NMN naturally decline as you age. Additionally, your ability to convert NMN to NAD+ decreases as you get older.

Since NAD+ levels decrease with age, researchers have been investigating if NAD+ and its precursors could be used to treat aging. To test this theory, they have conducted tests on animals and humans.

What Does Science Say About NAD for Aging?

Increased NAD levels may have benefits for many age-related diseases. So far, NAD has been studied in a number of health conditions, including:

In this section, we’ll talk about the evidence for using NAD and its precursors to treat or prevent certain age-related health conditions.

Neurological Conditions

Neurological conditions are conditions that affect your brain or spinal cord. Several small studies have looked at the effects of NAD and its precursors in people with Parkinson’s disease, Alzheimer's disease, and other types of dementia.

In clinical trials for humans with Parkinson’s disease, the results of NAD supplements have been mixed, with some positive results and others showing no effect.

Studies of NAD supplementation in animal models of Alzheimer’s disease have been promising. However, the results in humans with Alzheimer’s haven’t shown significant benefits.

Animal models of vascular dementia (dementia caused by an impaired blood supply to the brain) show that NMN supplements may improve brain function. However, human studies haven’t yet been done.

Skin Conditions

Growing evidence shows that lower levels of NAD+ in your skin as you age play an important role in your skin's appearance. DNA damage is one of the main causes of skin aging, primarily caused by UV light exposure. This is why the parts of your skin exposed to the sun, such as your face and hands, often age faster than other parts of your body.

Although NAD+ treatment for skin conditions is promising, there haven’t been many studies for this use. One small 2007 study found that applying an NAD+ ointment to the skin improved symptoms of psoriasis — a condition that causes itchy, scaly patches of skin. Researchers in this study found that NAD+ tends to break down in an ointment when it’s stored at room temperature. This means that to be effective, NAD+ skin treatments should be stabilized or stored in the refrigerator.

Metabolic Conditions

Metabolic conditions are health problems related to how your body processes energy. Diabetes, obesity, and high cholesterol are examples of metabolic conditions that get more common with age.

So far, there isn’t much research on the effect of NAD+ on metabolic conditions. Researchers think NAD+ or its precursors may help due to its effects on the regulation of energy metabolism. Early evidence shows that supplementation with NAD+ precursors may improve the balance of good to bad fats in the blood and prevent muscle breakdown in people who don’t exercise. The effect of NAD+ and its precursors on blood sugar regulation has been mixed. Some studies show that it can improve blood sugar regulation, while others show no effect or worse blood sugar control.

Future Research of NAD+ and NMN

Overall, more research is needed to understand the potential benefits and risks of NAD+ and NMN supplements. While many studies have been done in animals, only small studies have been completed in humans. It can be difficult to know if positive results in animal tests will translate into benefits for humans.

While there is a lot of evidence that suggests NAD+ and its precursors are likely safe and may be effective for many conditions, including aging, it hasn’t been proven in clinical trials. Future research may focus on clinical trials in humans with more people for longer periods of time. Additionally, clinical trials comparing the effect of NAD+ and its different precursors may be helpful.

How Do You Take NAD+ and NMN Supplements?

You should take NAD+ or NMN supplements exactly as directed on the label. The way you take an NAD+ or NMN supplement will depend on the product you’re taking. It’s important to note that the optimal dosage and safe dosage of NAD+, NMN, and other NAD+ precursors isn’t yet known.

There isn’t any research in humans about the best time in life to start an NAD+ supplement for anti-aging. Studies in mice suggest NAD+ and NAD+ boosting supplements may be most beneficial starting in middle age. NAD+ supplements may actually be harmful in younger people. Evidence in rats found that NAD+ boosting supplements actually decreased physical performance in young rats. However, it’s unknown if the same effect is true in humans.

What Are the Risks of Taking NAD+ and NMN?

As with any medication or supplement, NAD+ or NMN supplements may be associated with risks, including side effects, drug interactions, and safety concerns from contamination.

Side Effects

NAD+ and NMN studies haven’t reported any serious side effects. However, the studies on NAD+ and NMN in humans have only included a small group of people for a short time. We don’t know the effect of taking NAD+ at high doses over long periods of time. Additional studies with larger groups of people are needed to understand the effect. Potential concerns about the long-term use of supplements that increase NAD+ levels include increased inflammation and cancer-promoting effects.

Possible short-term side effects associated with NMN include:

Serious side effects associated with high doses of NAD+ precursors, such as nicotinamide and nicotinamide riboside, include liver toxicity and problems regulating blood sugar levels.

If you notice any new symptoms after you start taking an NAD+ or NMN supplement, talk to your health care provider right away.

Drug Interactions

NAD+ and NMN may interact with several different medications, including antidepressants and diabetes medications. Taking antidepressants with NAD+ may decrease NAD+ levels. If you’re taking diabetes medications to help control your blood sugar, NAD+ or NMN may affect how your body regulates blood sugar.

Other drug interactions are also possible. This is why it’s so important to talk to your health care provider before you start any new vitamin or supplement. Your health care provider may recommend more frequent monitoring or changing the dose of certain medications while taking an NAD+ or NMN supplement.

Contamination

Supplements containing NAD+ or NMN aren’t as strictly controlled as other prescription or over-the-counter medications. This means that there’s a possibility that harmful impurities may end up in your supplement. There also may be more or less of the active ingredient than the label says.

Should You Take an NAD+ or NMN Supplement for Aging?

Although the research shows that NAD+ is involved in many processes related to aging, there isn’t enough evidence to say for sure if an NAD+ or NMN supplement can stop or slow the process of aging. More research is needed to find out how NAD+ and NMN supplements will affect humans.

There are many NAD+ supplements available. Be aware of supplement companies that make claims that seem too good to be true — for example, products that claim they are a cure for aging. So far, the science does not back this claim.

Instead of an NAD+ or NMN supplement, consider adding foods rich in NAD+ precursors to your diet. Tryptophan and vitamin B3 are NAD+ precursors you can find in many foods.

Tryptophan-rich foods include:

Foods rich in vitamin B3 include:

Conclusion

NAD+ and NMN supplements have become increasingly popular in recent years. Early research in animals and small human studies show promising results for aging and many other age-related health conditions. However, there haven’t been enough clinical studies in humans to know for sure if NAD+ and NMN supplements are safe and effective. You should never use a supplement, such as NAD+ or NMN, to replace medical treatment.