Understanding NMN Safety: Potential Side Effects and Concerns

By The Wonderfeel Team

Story Index

Longevity science has made it clear that NMN, or nicotinamide mononucleotide, is working wonders. Its claim to fame is its ability to boost NAD in our cells — a pretty big deal. Since NAD is known as the fundamental driver of our health and a substance that begins to decline as we age, it’s not an exaggeration to call NMN one of the biggest scientific breakthroughs of our time. But it gets better. To date, no studies or anecdotal evidence have hinted at any sort of health risk or off-putting side effects. If you’re wondering about the safety of NMN, it’s all good.

NMN Side Effects: What Research Tells Us

A mix of rodent and human studies has raised approximately zero red flags when it comes to safety concerns (and tons of great news for fighting the hallmarks of aging). Let’s review:

  • A human clinical toxicity study conducted at Keio University in 2020 specifically focused on safety and concluded that NMN can be safely administered to people. Study participants took a daily dose of 100, 250, or 500 mg of NMN over a three-year span, with no negative side effects on physiological measurements like heart rate or blood pressure.
  • In 2021, a study looked at the effects of NMN and exercise on amateur runners over a six-week trial. There were three dosage groups of 300 mg, 600, and 1,200 mg per day. While this trial didn’t focus on safety, there were no negative side effects at any dosage. Incidentally, the biggest takeaway here was that aerobic capacity improved in the medium and high groups, which averages out to 900 mg daily as an optimal amount of NMN.
  • Another 2021 study from the University of Tokyo looked at the impact of 250 mg of NMN daily for 12 weeks. There were a number of improvements noted, but again, no negative side effects.
  • A study from the School of Medicine at Washington University also analyzed the effects of 250 mg of NMN per day, this time over a 10-week window. The older women who made up the participants in this trial had noticeable health changes for the better.
  • One of the most recent clinical trials – results will be published in 2022 – administered placebo, 300, 600, and 900 mg doses to people in four groups. No signs of toxicity were observed at any amount, and those in the 900 mg group experienced the most positive effects. 

Can I take 2000 mg NMN?

In a clinical trial led by Professor David Sinclair of Harvard Medical School in 2023 with people aged 55 to 80, it was found that taking NMN, even in large amounts including 2000 mg every day, is pretty safe and doesn’t cause any major side effects. For two weeks, the participants took either 1000 mg of a special type of NMN called MIB-626 once or twice a day, or just a dummy pill. The results were pretty clear: everyone, even those taking the largest doses, didn’t have any bad reactions, showing that our bodies handle NMN really well. This is great news because it confirms that NMN is safe for us to use in studies and might help with various health issues.

There are also several rodent studies showing that the administration of even high doses of NMN pose no toxicity or side effects. That’s notable, because a high dose of just about any drug on mice  almost always causes immediate side effects. The fact that NMN poses no issues can be considered quite reassuring.

Finally, let’s check in with the experts in the field. There’s Professor David Sinclair from Harvard Medical school, a leading authority in NMN and NAD science, who notes that “human studies with NAD boosters are on-going and so far, there has been no toxicity, not even a hint of it.”

Here at Wonderfeel, our Chief Medical Officer, Professor Andrew Salzman, a Harvard MD, whose groundbreaking discoveries led to more than fifty new medical treatments and over a hundred diseases, confirms that NMN is a very safe molecule for humans to take as a supplement.

Debunking Myths: NMN and Cancer

There are currently no indications or any research papers suggesting that NMN can cause cancer. On the contrary, researchers have shown that NAD supplementation can help fight cancerous tumors by boosting the efficacy of immune cells because when immune cells are activated to fight off cancer, they consume more NAD.  

However, we’d also like to mention that cancer cells require a lot of energy to grow and divide, and hence they demand more NAD. It’s been observed that various types of cancer cells rely on metabolic pathways which are regulated by NAD. There has been a small scale study with mice that have tumors where the researchers fed NR to mice, and observed that both cancer and non-cancer cells consume NR as expected.

A recent paper from 2022, explains this concept by examining the metabolic nutrition demand, -not specific to NR, showing how healthy cells and cancer consume the same nutrients.

Overall, there is no risk of cancer by taking NMN supplements, and as a recent paper published in 2021 concludes, NMN supplementation may be employed as adjuvant therapies for fighting cancerous tumors.

Is NMN toxic to the liver?

On the contrary, NMN has shown potential benefits for liver health, countering the notion of toxicity. It aids in reducing collagen deposits and problematic liver enzymes and prevents scar tissue build-up, crucial for maintaining liver function as we age. This promising research supports the role of NMN in enhancing liver health and aligns with Wonderfeel’s commitment to healthy aging and overall wellness.

Is NMN safe during pregnancy?

While NMN has been reported as effective for fertility treatment in some users, it’s important to proceed with caution when considering its safety during pregnancy. Currently, there is no research available on the effects of NMN in pregnant individuals. We strongly recommend consulting with a healthcare professional before introducing any new supplement during pregnancy. This ensures the best possible decision-making process for the health and well-being of both the mother and the baby.

Is NMN Safe for Dogs?

At Wonderfeel, we understand the importance of safety and well-being for all, including our furry companions. Recent research, including a study by Front Pharmacol, indicates that NMN can be well-tolerated by dogs when administered properly. 

The research focused on the subacute toxicity of NMN in mice and beagle dogs, assessing its effects when administered orally. In this study, the dogs showed only mild increases in certain blood markers with no significant adverse effects, suggesting that NMN could be safe for dogs. However, as every pet is unique, we recommend consulting with your veterinarian before introducing any new supplement to your dog’s routine. This ensures that any decision made is tailored to your pet’s specific health needs, aligning with our commitment to safe and responsible wellness practices.

The takeaway.

Of course, we’re not suggesting that endless amounts of NMN are perfectly fine. While people have a tendency to assume that more is always better, moderation is almost always a wiser strategy. After all, too much of just about anything, even water, can be harmful. (You can read about the optimal dose here.) And when it comes to NMN, the scientific research to date and leading authorities in the field of longevity science have all drawn the same conclusion — there is no evidence of any untoward side effects in reasonable doses, which means you can take your daily Wonderfeel NMN without worry. Wonderful news, isn’t it?

We send really good emails.

Plug into great insights in small bites and get periodic perks just for subscribers.

You may also enjoy these posts

3 min read

David Sinclair Approach: A Look at His Chosen Supplements

4 min read

Will NMN Help Me Sleep?

4 min read

Mushroom Power — The Benefits of Daily Ergothioneine

Discover the latest science and get subscriber only benefits.