Human studies show NMN is safe to take at high doses

Human studies show NMN is safe to take at high doses

Human NMN studies show that NMN is safe to take at high doses

Increased insulin sensitivity and oxygen consumption have been shown as safe at the highest human doses, ever recorded of taking NMN!

The growing list of benefits explored from a new human NMN study has never been so exciting! NMN Bio founder Dr Elena Seranova and David Florence, the host of the popular ‘Evolution of Dave’ YouTube channel, couldn’t wait to discuss these findings- click here

David has accrued more than 18,000 YouTube subscribers due to his health and fitness expertise. Whilst David frequently experiments with various supplements, he has chosen to continue NMN supplementation to boost his NAD+ levels for more than six months because of the benefits he feels, particularly the healing and added energy effects. Whilst many, like David, are already enjoying the long-term benefits of taking NMN, scientists have now been able to document the remarkable changes taking place inside the body by undertaking controlled human NMN studies.

A recent controlled human NMN study

Diving straight into the most recent study published in July 2021 – arguably with the most novel and exciting results – Dr Seranova takes us through what happened when scientists looked at the effects of a combination of exercise and supplementation with NMN on cardiovascular fitness in healthy amateur runners.

Dr Seranova explains, “They had 48 healthy participants from 27-50 years old, mixed gender adults, with an average BMI of 22.” She adds, “They were already running on a regular basis and those participants were separated into four groups taking 300mg, 600mg, 1200mg of NMN per day for six weeks or a placebo. Then they performed their aerobic training for six weeks, nearly every day, and their workouts lasted up to one hour - either running or cycling.”

Taking us through the results from the above graph, Dr Seranova explains, “This graph shows the ventilatory threshold 1, VT1, which is the stage where you start exercising and have more heavy breathing because you need more oxygen consumption. The VT2, the ventilatory threshold 2, is the phase where you're basically running out of breath because of the heavy exercise - and then further on, the maximum ventilatory capacity is when you stop your exercise because you can't go on.”

The results of those supplementing with NMN

So why were the results of those supplementing with NMN so remarkable? “NMN supplementation managed to increase the heart rate on VT1, which is very good because when your heart rate increases this means you can utilise oxygen and nutrients in the tissues better - so you're getting all the benefits of the exercise. They also saw increased oxygen consumption, improved power - which basically means strength, how you can keep on pushing during your exercise - and then increased maximum oxygen consumption during VT1. Overall, NMN supplementation managed to increase the VT1 threshold in the participants. During VT2, NMN supplementation managed to improve the power on the high NMN dosage. However, the other biomarkers that were measured here were not changed.”

Dr Seranova points out that some other measured biomarkers were unchanged at any stage, including various cardiopulmonary metrics such as maximum heart rate and maximum ventilation capacity in the lungs, but that “in the skeletal muscle-related function, when they performed the single-leg stance test, at 600mg of NMN per day they showed significant improvement in the performance of this test.” This indicates the improved performance was due to an improved ability of oxygen utilisation by skeletal muscles. “To summarise those results - after six weeks of endurance exercise combined with NMN supplementation, they showed that the VT1 threshold was increased, along with oxygen consumption and maximum oxygen consumption. In addition, with large doses of NMN, also managed to improve the power at the VT2 threshold.”  Certainly good news for runners and cyclists out there looking to improve!

As Dr Seranova explains, “Those results indicate that NMN supplementation was able to further increase the ventilatory threshold as a whole in those participants compared to exercise alone.” As David reflects on, “There is certainly in the West a bit of an obsession now for a lot of people around running and cycling and they're always looking to improve their capacity, especially aerobic capacity - this makes it a very interesting study for them.”

David, who takes 1g NMN a day, was curious to learn that some participants were taking 1.2g. Dr Seranova confirmed that this is to keep in line with previous mice experiments. “The 300, 600 and 1200mg of NMN in humans are the equivalent of 50, 100 and 200mg in mice.” Scientists, therefore, made sure participants were taking the equivalent amounts used in mice, for a human that weighs 60 kg, which will help to compare results from the numerous NMN mice studies already undertaken, including those showing the impact NMN has on longevity genes known as Sirtuins.

A key point of this latest cardiovascular fitness study is that it used the highest administration of NMN in humans so far – as Dr Seranova points out, “it shows the safety of the compound because none of the participants had any side effects.” What’s more, the NMN was only taken for six weeks in total – making the results even more outstanding in such a short space of time.

A study on the effects of NMN in Prediabetic women

Moving on to another key human study, published in April 2021, Dr Seranova and David discuss how prediabetic women who took 250mg of NMN for just 10 weeks showed increased insulin sensitivity and positively muscle remodelling. 

Dr Seranova outlined how the study showed “increased NAD intermediates, suggesting that there was a higher NAD turnover in tissues”. The significance of this, she explains, is “again, we validate the oral administration of NMN as being efficient in raising NAD levels and, of course, the fact that its increased insulin sensitivity is very nice to see – especially at a small dose of 250mg.” David agrees the ability of NMN to affect insulin sensitivity is remarkable to see.

A study on the effects of NMN and muscle tissue

Reflecting on a third human study from June 2021, where participants took 250mg NMN for 12 weeks, Dr Seranova explains that “NMN managed to raise NAD levels in serum and blood and also prevented the age-related muscle dysfunction.” The impact of NMN on muscle tissue is becoming very clear. As Dr Seranova explains, “Three out of three studies that we mentioned today show the muscle tissue being quite sensitive to NMN supplementation and responding very well to it.”

At what age can we start supplementing with NMN?

As the benefits of supplementing with NMN become more apparent with each new human study, the question of when to start taking NMN is on a lot of people’s minds.

One of David’s 18,000 YouTube subscribers asked if at the age of 21 he should be taking NMN but both David and Dr Seranova agree it’s only when the ageing process kicks in – and NAD+ levels start to decline – that it’s a good time to start.

If you’re chomping at the bit to get started, Dr Seranova thinks 27 is the magic number. “We have the peak of NAD hormonal production at 25, you don't really need to take anything like that at this age. After 25, probably around 27, is when you start experiencing increased fatigue and so on, so I think that this would be the ideal age to start supplementing with NAD boosters and other anti-ageing supplements.” Either way, it’s key to focus on what works for you personally, as David explains, “The important message I think of supplementations, not just to do with NMN but any kind of supplementations, is that you have to conduct your own study.”


As for the official human studies, this now brings the total number to date to four – the three discussed in detail here and an initial early study demonstrating the safety of taking 500mg of NMN. The results of these human studies are already brilliant news for many different types of people. Significantly, for runners and cyclists looking to improve your performance, as well as other amateur athletes – as David points out these results no doubt have bodybuilder enthusiasts excited too! It’s also great news for prediabetics hoping to keep diabetes at bay, and for anyone wishing to take NMN for its anti-ageing effects but who have been waiting on scientific proof of the safety of high doses – that news is in!

With three key studies already published in 2021 alone, it paves the way for further studies to show the benefits of taking NMN on a longer-term basis, as well as to show what taking NMN can do for participants who are elderly, and not as fit and healthy, where the results are likely to be even more profound. Both David and Dr Seranova now expect to see more and more human studies ahead – and we can’t wait to share the results!


  1. Liao B, Zhao Y, Wang D, Zhang X, Hao X, Hu M. Nicotinamide mononucleotide supplementation enhances aerobic capacity in amateur runners: a randomized, double-blind study. J Int Soc Sports Nutr. 2021;18(1):54. Published 2021 Jul 8. doi:10.1186/s12970-021-00442-4
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