NMN vs. NR: What's The Difference Between These 2 Buzzy Supplements?

As science continues to discover the mechanisms behind what happens to our bodies as we age, we are finding there are many ways to optimize health—even down to a cellular level.

One area that has gained a lot of interest lately is nicotinamide adenine dinucleotide (NAD+), a coenzyme responsible for cell metabolic activity and energy production, and its role in slowing down the physical and mental changes of aging. We know that NAD+ decreases as we get older—but we also know you can support your levels through supplementation. This includes the buzzy nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN) supplements. While they both support the production of NAD+, there are differences in how they work and the science behind them.

What are the differences between NR and NMN?

Research done on rodents has found that both NR and NMN can support NAD+ levels in various tissues1, including the brain. These studies also show that these compounds may have a positive effect on glucose tolerance, mitochondrial function, and other conditions.

Some studies on rodents2 also suggest that NMN may work better for certain conditions, such as age-related cognitive decline. But in terms of human clinical studies, Sommer White, M.D., an integrative and functional medicine physician, says "NR has the most evidence to back up its effectiveness."

Here is a summary of what we know about these two supplements.

What is NR?

Nicotinamide riboside (NR) is a precursor for NAD+ and a form of vitamin B3. It is first converted to nicotinamide mononucleotide (NMN), which is then converted to NAD+.

NR can be found naturally in food: "Milk3 and yeast products are a source of NR," says White, and milk also contains other NAD+ precursors in smaller amounts. However, he doesn't recommend using these as your source since the volume you'd have to consume to get the benefits would be too great. NR supplements are much more effective at supporting NAD+ levels in the body.

The research bears out NR supplement use—several human clinical trials of NR supplements have been completed, including randomized placebo-controlled trials (RCTs), the "gold standard" of clinical research. In one eight-week study4, researchers found that people taking NR had an increase in their blood NAD+ levels. Healthy overweight adults tolerated a daily oral NR dose of up to 1,000 milligrams, with no flushing or serious side effects. Another study5 showed that NR is more bioavailable, or has better absorption, than nicotinamide and nicotinic acid.

A recap of nicotinamide riboside (NR):

What is NMN?

Nicotinamide mononucleotide (NMN) is a direct precursor to NAD+. In mammals, NMN can be made from nicotinamide (another form of vitamin B3) or nicotinamide riboside. The conversion from nicotinamide involves the enzyme NAMPT.

Scientists are not certain how NMN gets into the cells1. It may be transported directly or may require more cofactors—such as vitamins and antioxidants—to make the process work smoothly.

NMN occurs naturally in various foods8. The highest amounts are found in edamame, broccoli, cucumber, and cabbage. Moderate amounts are present in avocado and tomato. Smaller amounts show up in raw beef, shrimp, cow milk, and human breast milk9. Because of a the low levels of NMN in these foods, NMN supplements may be a more effective way to increase levels and a few NMN supplements are currently available.

Most studies on the safety of NMN have been done in rodents8. Only one safety study of NMN10 done in people has been published. In this clinical trial, researchers found that a single dose of up to 500 mg of NMN didn't cause any serious side effects. Several clinical trials of NMN in the United States and other countries are currently underway or recently completed.

A recap of nicotinamide mononucleotide (NMN):

The takeaway

As the results of the NMN clinical trials that are currently underway are published, it will become clearer whether NMN will work as a supplement for healthy aging. Right now, with several clinical trials already completed in people, the science behind NR is more encouraging. "Nicotinamide riboside shows a lot of promise," says integrative physician Robert Rountree, M.D., "and it works best when combined with additional nutraceuticals such as antioxidants like astaxanthin and adaptogenic herbs like Rhodiola rosea."

If you are pregnant, breastfeeding, or taking medications, consult with your doctor before starting a supplement routine. It is always optimal to consult with a health care provider when considering what supplements are right for you.