Can raising your body’s NAD⁺ levels actually slow aging—or is the science still catching up to the hype? A comprehensive review of more than 100 scientific studies provides one of the clearest answers yet.
The Growing Interest in NAD⁺
Over the past several years, NAD⁺ (Nicotinamide Adenine Dinucleotide) has become one of the most talked-about molecules in longevity research. Scientists have discovered that NAD⁺ plays a vital role in nearly every cell in the body, helping convert food into energy, supporting healthy mitochondria, repairing damaged DNA, and activating proteins involved in healthy aging.
Unfortunately, NAD⁺ levels naturally decline as we get older.
This decline has led researchers to investigate whether restoring NAD+ levels through supplementation could improve health, support healthy aging, and possibly reduce some of the effects associated with growing older.
But does increasing NAD⁺ actually translate into better health?
To answer that question, researchers recently published one of the most comprehensive reviews to date, analyzing more than 113 scientific studies examining NAD⁺ supplementation in both humans and animals.
Key Finding
Researchers reviewed 113 published studies, including 33 human clinical studies and 80 animal studies, making this one of the most comprehensive evaluations of NAD⁺ supplementation currently available.
What Is NAD⁺?
NAD⁺ is a naturally occurring coenzyme found in every living cell. Without it, our cells would struggle to produce energy or repair themselves efficiently.
Scientists have linked declining NAD⁺ levels with many age-related changes, including:
- Reduced cellular energy production
- Less efficient DNA repair
- Mitochondrial dysfunction
- Increased inflammation
- Reduced metabolic function
Because of this, researchers have been exploring ways to restore NAD⁺ levels using supplements such as:
- Nicotinamide Mononucleotide (NMN)
- Nicotinamide Riboside (NR)
- NAD⁺ injections
- NAD⁺ intravenous (IV) therapy
How Was This Research Conducted?
Rather than performing a single experiment, the researchers completed a PRISMA-guided systematic review, one of the highest standards for evaluating scientific evidence.
They carefully analyzed research published between 2010 and 2025, comparing findings from animal models and human clinical trials.
This approach helps reduce bias and provides a much clearer picture of what the overall body of evidence actually shows.
Study Snapshot
✔ 113 total studies reviewed
✔ 33 human studies
✔ 80 animal studies
✔ Research published over approximately 15 years
What Did the Animal Studies Show?
The results from animal research were highly encouraging.
Across many studies, increasing NAD⁺ levels was associated with improvements in several important markers of healthy aging.
Researchers observed:
- Improved mitochondrial function
- Better energy metabolism
- Reduced inflammation
- Improved muscle function
- Better physical performance
- Improvements in several age-related biological processes
Although not every study produced identical results, the overall trend suggested that boosting NAD⁺ positively influenced many systems involved in aging.
What Happened in Human Studies?
The human evidence painted a more cautious picture.
One finding was remarkably consistent:
NMN and NR successfully increased NAD⁺ levels in the body.
This means the supplements achieved exactly what they were designed to do biologically.
Important Takeaway
Increasing a biological marker does not automatically mean people will experience noticeable improvements in health. This review found strong evidence that NAD⁺ levels rise after supplementation, but much weaker evidence that this consistently translates into measurable anti-aging benefits in humans.
What About NAD⁺ IV Therapy?
One of the most interesting findings involved NAD⁺ IV infusions.
Despite their growing popularity in wellness clinics, researchers found very limited clinical evidence supporting their use for healthy aging.
The review identified:
- No clinical trials demonstrating anti-aging benefits from intravenous NAD⁺ itself.
- Only one small intravenous NMN study focused primarily on safety and biological markers.
- A pharmacokinetic study explaining how IV NAD⁺ moves through the body, but not whether it improves longevity or health outcomes.
This doesn’t necessarily mean IV therapy is ineffective—it simply means the scientific evidence remains very limited.
Is NAD⁺ Supplementation Safe?
Overall, the news was encouraging.
Across the clinical studies reviewed, NMN and NR were generally well tolerated.
Most participants experienced few serious side effects during the study periods.
However, researchers emphasized that much longer clinical trials are still needed to fully understand long-term safety and effectiveness.
Safety Summary
Current evidence suggests oral NMN and NR appear to have favorable short-term safety profiles in healthy adults. Long-term studies are still underway.
What Does This Mean for Healthy Aging?
This review reached a balanced conclusion.
The science strongly supports that NAD⁺ supplementation can successfully increase NAD⁺ levels within the body.
What remains uncertain is whether those increases consistently produce meaningful improvements in lifespan, physical function, or overall healthy aging in humans.
That doesn’t mean the approach lacks promise.
Instead, it highlights an important reality of scientific research:
Many therapies first demonstrate biological effects before researchers can determine whether those effects translate into long-term clinical benefits.
The authors conclude that larger, longer-duration clinical trials are needed before definitive claims can be made regarding NAD⁺ supplementation and longevity.
Final Thoughts
NAD⁺ remains one of the most exciting areas of aging research.
This comprehensive review confirms that scientists have uncovered an important biological pathway involved in cellular health and aging. At the same time, it reminds us that good science requires careful evaluation—not assumptions.
The evidence today suggests that NAD⁺ supplementation is scientifically promising, appears generally well tolerated, and reliably raises NAD⁺ levels. However, whether those changes consistently improve long-term human health is a question researchers are still working to answer.
As new clinical trials are completed, our understanding of NAD⁺’s role in healthy aging will continue to evolve.
“Promising science today. Stronger clinical answers tomorrow.” – Crownwell Research
Original Research
NAD⁺ Supplementation for Anti-Aging and Wellness: A PRISMA-Guided Systematic Review of Preclinical and Clinical Evidence
