NMN vs NR: Which Is Better?

Both NMN and NR safely raise NAD+. No head-to-head human trial proves one superior. NMN may act more directly in some tissues, while NR has broader human data. 

Both molecules follow the salvage pathway but enter at different steps, and take different paths to get there. For many people, consistent use matters more than choosing a single “winner.”

However, we can still compare them. So in this article, we will do exactly that. We will learn more about how NR and NMN go head-to-head with each other. We will discover their chemistry, biology, and even safety! Ready to dive in?

What Are NMN And NR, Exactly?

Nicotinamide mononucleotide (NMN) and nicotinamide riboside (NR) are precursors to NAD+. This means when you take NR or NMN as a supplement, your body can use them to produce more NAD+. 

Can You Get NMN And NR From Diet Alone?

Both NMN and NR exist naturally in our diet in trace amounts. Here’s how much NMN and NR you can get from food:

• NR: 1 mg/L of milk

• NMN: 1 mg/100g of food (edamame, broccoli, and meat). 

But as you can probably tell, we can’t realistically eat enough of those foods to significantly boost NAD+ levels. That’s why concentrated supplements of NR and NMN have become popular for supporting cellular energy and healthy aging.

For instance, to get the same amount of NMN as in a capsule (500 mg), you would have to eat about 110 lbs of meat, or broccoli or edamame. As you can tell, that’s rather inconvenient. 

What Is The Difference Between NR And NMN?

Molecularly, NMN and NR are very similar – with one key difference. NR is simply a nicotinamide base attached to a ribose sugar. NMN is essentially an NR molecule with an added phosphate group. 

In other words, NMN is a phosphorylated form of NR. This makes NMN a slightly larger molecule than NR. Why does that matter? That phosphate group means NMN is one step closer to NAD+ in the body’s conversion pathway. In fact, cells convert NR into NMN as an intermediate step toward NAD+. 

How NMN And NR Are Converted To NAD+ In Cells?

Both NR and NMN ultimately feed into the body’s “NAD+ salvage pathway,” which recycles components to make new NAD+. But they enter this pathway at slightly different points:

• NR’s Pathway: When NR enters a cell, it is first converted into NMN by an enzyme called NRK (nicotinamide riboside kinase). NR becomes NMN through phosphorylation. NMNAT then adds an adenine group to create NAD+. Various enzymes, including sirtuins, utilize NAD+ for DNA repair and metabolism. The body eventually breaks NAD+ down into nicotinamide (vitamin B3). NAMPT then recycles that nicotinamide back into NMN, continuing the cycle.

  
  

• NMN’s Pathway: NMN is already one step ahead – it doesn’t require NRK because it’s already “phosphorylated.” Once NMN is inside a cell, NMNAT can act on it directly to convert NMN into NAD+. In essence, NMN is the last direct precursor in the assembly line before NAD+ is made. This theoretically makes NMN a very efficient route to boost NAD.

Absorption & Bioavailability: Does One Get Into Cells Better?

NMN likely has an advantage over NR because it has a dedicated transporter (Slc12a8) that helps it get inside cells. 

A big question for any supplement is bioavailability – how well it’s absorbed and utilized. At first glance, NR’s smaller size suggested it might cross cell membranes more easily than NMN. However, new research complicates this simple picture. 

How NMN Gets Inside Cells?

Scientists discovered a specific NMN transporter protein in the gut of mice, known as Slc12a8, that can shuttle NMN directly into cells. This was a groundbreaking find. It meant NMN doesn’t always need to become NR to get into cells – at least not in tissues where this transporter is present. 

How NR Gets Inside Cells?

On the other hand, NR has its own ways of getting into cells. NR is taken up via Vitamin B3 transporters. Once inside, it quickly converts to NMN so that it can be used in the NAD+ salvage pathway. 

Bottom line on absorption: Both NR and NMN are effectively absorbed and raise NAD+ levels, but they take different routes. NR’s small size allows it to slip into most cells freely. However, NMN often relies on specific transporters or conversion to NR for entry. 

Which Raises NAD+ Levels More?

Ultimately, the efficacy of NMN or NR as a supplement comes down to whether they boost NAD+ in the body, and by how much? According to current research, both can significantly increase NAD+ levels, though much of the data comes from small trials.

Does NR Raise NAD+ Levels?

Pioneering research by Dr. Charles Brenner and colleagues showed that a single oral dose of NR raised NAD+ levels. The increase in human blood was up to 2.7-fold (relative to baseline) within hours. 

• 22% increase at 100 mg

• 51% increase at 300 mg

• 142% increase at 1,000 mg 

These NAD gains persisted through the 8-week study, and importantly, no serious side effects were noted.

Another notable trial looked at NR in middle-aged and older adults (55–79 years) for 6 weeks. NR (500 mg twice daily) raised NAD+ in white blood cells by approximately 60% compared to placebo. 

Does NMN Raise NAD+ Levels?

A groundbreaking 2021 study from Washington University tested NMN (250 mg per day) in postmenopausal women with prediabetes over 10 weeks. The findings, published in Science, showed that NMN significantly increased NAD+ levels in blood cells and also improved muscle insulin sensitivity. 

Specifically, muscle tissue became more responsive to insulin, meaning better uptake of glucose for energy. This was the first direct evidence of NMN improving a metabolic function in humans. 

Interestingly, NMN did not lower blood glucose or blood lipids in that short timeframe, nor did it change blood pressure. But the improvement in muscle insulin action suggests it could help ward off type-2 diabetes in at-risk individuals. 

The women taking NMN also had changes in muscle gene expression related to structure and remodeling, hinting at enhanced muscle health.

Another trial, out of Japan, studied NMN in healthy older men (mean age ~75) at 250 mg/day for 12 weeks. The results, published in 2022, showed that NMN supplementation significantly raised NAD+ levels in the blood of these older adults. 

So Which One Raises NAD+ More? 

There’s no head-to-head human trial yet directly comparing NMN to NR in the same population and conditions. However, based on available data, both can at least significantly increase NAD+ levels in the blood. This is especially true at higher doses or with sustained use. 

NR might have a slight edge in the magnitude of NAD+ boost observed in some studies (e.g. +142% in 2 weeks at 1 gram. However, NMN has shown meaningful NAD increases even at a moderate 250 mg dose over longer periods. 

Importantly, both compounds effectively overcome the age-related NAD decline. And they bring older individuals’ NAD+ levels closer to those seen in youth. 

Are NMN And NR Safe To Take?

Safety is a primary concern for anyone considering a new supplement. The good news is that human studies so far report NMN and NR to be remarkably safe and well-tolerated, even at relatively high doses.

NMN Safety Profile

Early human trials of NMN have not flagged any serious side effects. Let’s take a look at some of the current human studies and their doses:

• 100 - 500 mg: A 2020 study in Japan gave healthy men single doses of NMN ranging from 100 mg up to 500 mg and found no adverse symptoms or significant changes. 

• 1250 mg: More recently, a 2022 clinical trial in Japan tested daily NMN doses as high as 1,250 mg per day for 4 weeks in healthy men and women. Again, no serious adverse events were observed and the NMN was well tolerated. 

• 2000 mg: Similarly one clinical trial took it even further to over 2000 mg/day (2 doses of 1000 mg). That team also reported no serious side-effects. 

NR Safety Profile 

NR has been studied in humans since earlier, and across numerous trials it also shows a strong safety profile. Again, let’s review safety against dose:

• 100 - 1000 mg: In a 8-week trial mentioned earlier, NR at 100, 300, and 1,000 mg per day caused no difference in adverse effects compared to placebo. Not even at the highest dose.

• 1000 mg for 6-12 weeks: Another study gave overweight adults 1,000 mg of NR daily for 6–12 weeks. While NR was well tolerated, some participants noted mild issues like nausea or fatigue. However, these problems were infrequent and sometimes appeared in placebo groups as well. 

• 3000 mg: A recent trial in Parkinson’s disease tested very high-dose NR at 3,000 mg per day. And even at 3 grams daily, NR was well tolerated with no moderate or severe adverse events observed over the one-month study. 

NMN vs NR – Which Should You Choose?

When comparing NMN vs NR, the key thing to remember is that both of these NAD+ precursors work toward the same goal. They both support your cells’ energy metabolism and longevity pathways by raising NAD+ levels. 

At this stage, calling one “better” than the other is premature. NMN might have a slight edge in certain tissues or functions. On the other hand, NR has the head start in human research. But these distinctions are not yet well-defined. Many experts see them as complementary tools rather than competitors.

The good news is you don’t necessarily have to choose one exclusively. What’s most important is taking a high-quality NAD+ booster consistently, at an effective dose. to help combat age-related NAD+ decline. Whether that’s NR, NMN, or a combination may be less critical than simply ensuring your NAD+ tank is refilled.

If you’re ready to take the next step in supporting healthy aging at the cellular level, why not start with a proven NAD+ booster: Ultra Pure NMN™? After all, you have nothing to lose – and so many years to regain!

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