The anti-aging coenzyme craze is no longer reserved for A-listers and biohackers.
By now, most of us have heard about nicotinamide adenine dinucleotide, better known as NAD. NAD is a cellular compound found in all living organisms. It plays a critical role in hundreds of bodily functions, including supporting cellular health, energy production and DNA repair.
Research also indicates that NAD levels decline in human brains with age, which has prompted more people to look into various NAD-boosting treatments. Celebs have been seen with their NAD+ IV drops, while longevity enthusiasts have explored different supplements, from powders to pills.
However, understanding NAD requires understanding NMN (nicotinamide mononucleotide), its immediate precursor. Researchers have spent years studying the relationship between NMN and NAD.
Dr. Andrew Salzman, a physician from Harvard Medical School and Chief Medical Officer of wellness biosciences company Wonderfeel, has emphasized that the key to restoring NAD levels may not be NAD itself — but the compounds that help the body produce it.
Unlike the larger NAD molecule, NMN is smaller. Scientists like Salzman believe NMN has greater potential for uptake into certain tissues throughout the body. Once inside the cell, NMN can easily convert into NAD, helping replenish the body’s levels of the essential cellular compound.
While NMN is well-researched, it has not always been widely available online.
In 2022, the FDA banned the marketing of NMN as a dietary supplement while it was still being investigated as a drug. But in 2025, the FDA reversed its position, allowing NMN supplements to re-enter the market. Today, thousands of brands offer NMN supplements in a variety of formulas and formats, with different standards for testing and production.
Since NMN is a relatively new addition to the longevity supplement space, many people may be wondering what to look for when choosing a high-quality NMN supplement in 2026 — as well as the proper dosage, timing and whether there are side effects to consider.
Wonderfeel Youngr, the brand’s award-winning flagship NMN supplement, delivers 900 milligrams of NMN with third-party testing, cGMP-certified production and thousands of customer reviews.
“NAD itself cannot be swallowed and expected to cross the gut into the blood and get into our cells,” Salzman reiterated. “That’s why we need precursors like NMN and NR, which use nature’s own transport system to get into our cells.”
In addition to a clinically-backed dose of NMN, Wonderfeel Youngr combines antioxidants like resveratrol, ergothioneine, hydroxytyrosol and Vitamin D3 to fight oxidative stress and support cellular health.
“Just to give NMN without protecting against oxidant stress would be only half the story. Our focus at Wonderfeel is on getting mitochondria back to full health. By giving antioxidants, we nurture, we potentiate the efficacy, we augment the effect of NMN,” he added.
What are the science-backed benefits of NMN supplements?
Salzman has described NAD as the “centerpiece of biology,” which is why boosting NAD levels with NMN may provide a wide range of benefits, including improved mitochondrial function, reduced inflammation, enhanced insulin sensitivity, greater athletic performance and even healthier skin.
“The diseases are just leaves on the trees. We need to go to the roots and the trunk of what’s really going on with our biology,” Salzman explained. “When you look at NAD, the mechanism of action, it does so many different things from DNA repair to the activation of sirtuins to increasing energy production in the cell to reducing inflammation, boosting mitochondrial function and improving insulin resistance.”
Clinical research supports several of these potential benefits.
- In one small trial, women with prediabetes who took NMN for 10 weeks showed improved muscle insulin sensitivity and glucose utilization.
- Another study of amateur runners found improvements in VO2 and VO2 max, concluding that NMN increased aerobic exercise capacity.
- Additional research suggests that NMN can enter human skin cells and increase hyaluronic acid production, which may help improve skin hydration, elasticity, and firmness.
Can NMN increase your lifespan?
While no human studies have shown that NMN supplements extend lifespan, animal research has produced promising results. A 2023 study found that increasing NAD+ levels with NMN supplementation was associated with longer lifespans in mice.
“NMN treatment delayed the onset of frailty in both sexes, improved metabolic health in male mice, and increased median lifespan by 8.5% in female mice,” the study noted.
More research is needed before linking NMN supplementation to extended lifespan in humans.
How should you take NMN — IV, injections or capsules?
There are several options when it comes to NMN delivery methods. NMN capsules are the most popular and accessible option. While celebrity endorsements have increased interest in NAD injections and NAD intravenous infusions (IV), the clinical research on those methods remains limited.
Some experts have raised concerns that these alternative methods can not effectively raise NAD levels.
“We now know that it can’t be done by delivering NAD either orally or by IV — because NAD has no mechanism for entering the cell,” explained Salzman.
- The IV approach delivers NAD directly into the bloodstream, but it’s unclear how much reaches the cells and tissues where it’s needed. A 2019 study found that much of the NAD administered intravenously over six hours was ultimately excreted in the urine.
- As for injections, there are similar concerns regarding crossing cell membranes. Injections could also potentially cause discomfort at the injection spot and other side effects such as mild headaches or an elevated heart rate.
- Most scientific studies in humans have used an NMN pill that participants took orally. This method also allows users to gradually tailor their dosage over time, and experts like Salzman emphasize that the oral method ensures that the NMN is absorbed and converted into NAD in the cells.
What should you look for in a high-quality NMN supplement?
There are several important factors to consider when choosing an NMN supplement. Purity is key, which is why experts like Salzman suggest selecting a product that has been tested to ensure it is free of contaminants such as toxins, yeast, mold and other impurities.
To help verify quality, choose an NMN supplement that is manufactured in a cGMP-certified facility and independently tested by a third-party laboratory, with lab results available for customers to review. These measures help confirm that the NMN supplement meets quality and safety standards.
It’s also important to check the ingredient list. High-quality NMN supplements should be free from unnecessary binders, fillers, artificial dyes, and other additives that don’t contribute to the product’s effectiveness. For review, consider the following before purchasing an NMN product:
- cGMP-certified: cGMP-certified, meaning the product meets FDA regulations that ensure every product hits the highest marks for quality, purity and effectiveness.
- Certificate of Analysis (COA): A COA verifies that the product has been tested for identity, purity and potency.
- QR code on the COA or packaging: Many accredited labs allow users to verify the test results directly with the issuing lab, adding another layer of transparency.
How much NMN should you take each day?
Research has compared the effects of NMN at different dosages and found that higher doses were the most effective at increasing NAD levels.
One recent clinical trial evaluated 80 participants who were randomly assigned to one of four NMN dosage groups and followed for 60 days.
Researchers measured three key outcomes before and after the study, including blood NAD levels, performance during a walking test, and results from the SF-36 health survey, an internationally recognized questionnaire that measures overall health and quality of life.
After reviewing the findings, Dr. Salzman noted that all three NMN treatment groups performed substantially better than the placebo group across all measured outcomes. Based on the median results, the 900 milligrams group demonstrated the greatest overall improvements.
Wonderfeel NMN provides a 900 milligrams daily dose, matching the dosage shown to produce the greatest benefits in this clinical research.
Are there any side effects of NMN supplements?
While the Cleveland Clinic notes that some people may experience mild side effects with NAD supplements, such as nausea or headaches, clinical research has generally found NMN to be well tolerated and safe.
A 2022 safety evaluation looked into several clinical trials, considering the effects of taking NMN daily for four weeks on a group of healthy adult men and women. The results found that NMN supplementation did not cause any side effects, and the researchers concluded that it is both “safe and tolerated” at oral doses up to 1250 milligrams.
Another 2023 clinical trial led by Harvard Medical Professor David Sinclair reinforced the compound’s safety. In this study, participants upped the dose to 2,000 milligrams a day, and the researchers still found no adverse effects.
Who should avoid taking NMN?
While studies suggest that NMN is safe and well tolerated for most adults, it’s important to consult your healthcare provider before starting any new supplement, especially if you have an underlying medical condition or take prescription medications.
Certain groups should avoid NMN until more research is available, including people who are pregnant or breastfeeding, as its safety during pregnancy has not yet been established through clinical research.
This article was written by Miska Salemann, New York Post Commerce Writer/Reporter. As a health-forward member of Gen Z, Miska seeks out experts to weigh in on the benefits, safety and designs of both trending and tried-and-true fitness equipment, workout clothing, dietary supplements and more. Taking matters into her own hands, Miska intrepidly tests wellness products, ranging from Bryan Johnson’s Blueprint Longevity Mix to the viral Oura Ring to Jennifer Aniston’s favorite workout platform – often with her adorable toddler by her side. Before joining The Post, Miska covered lifestyle and consumer topics for the U.S. Sun and The Cannon Beach Gazette.
