Does NAD+ Therapy Work? What Human Research Actually Shows

Quick answer: NAD+ is a coenzyme that declines with age, and boosting it improves several outcomes in animal studies. In humans, a 2026 systematic review found that oral precursors (NR, NMN) reliably raise NAD-related blood markers and are generally well tolerated. But clinical benefits were mixed, and no outcomes trials tested IV NAD+ for anti-aging or wellness.

What NAD+ is, in one paragraph

Nicotinamide adenine dinucleotide (NAD+) is a molecule every cell uses. It carries electrons for energy metabolism and acts as a signal for enzymes involved in DNA repair and cell survival. A widely cited 2018 review from Harvard Medical School researchers in Cell Metabolism notes that NAD+ levels steadily decline with age, and that restoring NAD+ in old or diseased animals can improve health markers and extend lifespan in those animal models. That animal work is the main reason NAD+ became a wellness topic.

The key question for anyone considering NAD+ is whether those animal findings carry over to people. Here is what the human evidence says so far.

The short version of the human evidence

What a 2026 systematic review found

A PRISMA-guided systematic review published in Ageing Research Reviews in 2026 screened human and rodent studies from 2010 to October 2025. It included 33 human intervention studies (28 randomized) and 80 rodent studies. The authors reported:

• In rodents, NAD+ augmentation was frequently linked to better metabolic, mitochondrial, inflammatory, and functional outcomes. Effects varied by model.
• In humans, oral nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN) consistently raised NAD-related metabolites in blood or cells and were generally well tolerated over weeks to months.
• Effects on functional, metabolic, vascular, and other healthspan outcomes were heterogeneous and often null or endpoint-specific.
• No eligible outcomes trials evaluated intravenous or intramuscular NAD+ itself for anti-aging or wellness uses.
• The authors concluded that NAD+ augmentation shows clear biological activity, but clinical effectiveness for anti-aging or wellness outcomes remains inconclusive.

A second systematic review

A 2024 systematic review in the American Journal of Physiology–Endocrinology and Metabolism looked at 10 randomized trials (489 participants) of NAD+, NADH, and precursors across conditions such as chronic fatigue syndrome, Parkinson's disease, overweight, and postmenopausal prediabetes. Supplementation was generally well tolerated. All studies reported some side effects, most often muscle pain, nervous system complaints, fatigue, sleep disturbance, and headaches. The authors reported no serious adverse events in the trials they reviewed.

One frequently cited positive trial

People often point to a 2021 Science trial from Washington University School of Medicine. In a 10-week randomized, double-blind, placebo-controlled study, postmenopausal women with prediabetes and overweight or obesity took NMN. Muscle insulin sensitivity and insulin signaling improved with NMN and did not change with placebo.

That is a real, well-designed result. It is also narrow: one population, one precursor, one set of endpoints, a short time frame. It does not show that NAD+ products slow aging, and it did not test IV NAD+.

What we know about IV NAD+ specifically

IV NAD+ is common in wellness settings, but the human research on it is thin.

• Pharmacokinetics. A 2019 pilot study in Frontiers in Aging Neuroscience tracked blood and urine during a 6-hour IV NAD+ infusion. Surprisingly, plasma NAD+ and its measured metabolites did not change for the first 2 hours. The authors concluded that infused NAD+ was rapidly and completely cleared from plasma during that window. NAD+ and methylnicotinamide later appeared in urine.
• Outcomes. As noted above, the 2026 systematic review found no eligible outcomes trials testing IV or intramuscular NAD+ for anti-aging or wellness. It treated the IV pharmacokinetic pilot as context only.

So the honest answer to "does IV NAD+ work for energy or aging?" is that controlled human outcome data are not there yet. That doesn't mean people never report feeling different. It means the science hasn't measured it in a way that supports a claim.

Regulatory reality

NAD+ infusions are not an FDA-approved treatment for aging, fatigue, or wellness. When any infusion is compounded, FDA states that compounded drugs are not FDA-approved, and FDA does not verify their safety, effectiveness, or quality before they are marketed. Ask who prepares the product and under what pharmacy license.

How to think about NAD+ as a patient

Questions worth asking any clinic

1. What human evidence supports this for my specific goal, and what endpoints did it measure?
2. Is this an oral precursor, an injection, or an infusion? Why that route?
3. Who compounds it, and is the pharmacy state-licensed?
4. What side effects have been reported, and how will you monitor me?
5. What would make us decide it isn't worth continuing?

Where NAD+ fits in a broader plan

NIH's National Institute on Aging emphasizes that exercise, a healthy diet, sleep, limited alcohol, and regular medical care are within our reach for supporting healthy aging. Any NAD+ conversation should sit inside that larger plan, not replace it. At Regen Therapy MD, a physician reviews your history before discussing whether any infusion or supplement is reasonable for you, or whether it isn't.

Frequently asked questions

Does NAD+ IV therapy work?

There are not yet controlled human outcome trials showing that IV NAD+ improves aging or wellness outcomes. A 2026 systematic review found no eligible outcomes trials of IV or intramuscular NAD+ for those uses. A small 2019 pilot measured how infused NAD+ moves through blood and urine, but it did not test benefits.

Do NMN or NR supplements raise NAD+ levels?

Yes, in human studies. The 2026 Ageing Research Reviews systematic review reported that oral NR and NMN consistently raised NAD-related metabolites in blood or cells and were generally well tolerated over weeks to months. Raising a blood marker is not the same as improving health outcomes, and those results were mixed.

Is NAD+ safe?

In a 2024 systematic review of 10 randomized trials, NADH and NAD+ precursors were generally well tolerated. Reported side effects included muscle pain, fatigue, sleep disturbance, and headaches, with no serious adverse events in those trials. Safety depends on the product, the route, and your health history, so talk with a clinician.

Does NAD+ slow aging?

Not in a way that has been demonstrated in people. Animal studies show NAD+ restoration can improve health markers and extend lifespan in those models. In humans, a 2026 systematic review called clinical effectiveness for anti-aging outcomes inconclusive and called for larger, longer randomized trials.

Is NAD+ IV FDA-approved?

NAD+ infusion is not an FDA-approved treatment for aging, fatigue, or general wellness. If a product is compounded, FDA states that compounded drugs are not FDA-approved and are not reviewed for safety, effectiveness, or quality before marketing.

Talk with a Regen Therapy MD physician

If you'd like to talk through whether any of these options fit your health history, start with a physician consult, not a product.

• Book a consult: https://book.mypatientnow.com/practice/TqZLiT
• Call: (424) 349-6008
• Cost: $295 consult (physician visit)
• Clinics: Beverly Hills and Santa Monica. Telehealth and peptide shipping are available only where we are licensed.

Sources

1. Rajman L, Chwalek K, Sinclair DA. Therapeutic Potential of NAD-Boosting Molecules: The In Vivo Evidence. Cell Metab. 2018. PMID 29514064. https://pubmed.ncbi.nlm.nih.gov/29514064/
2. Gallagher C, Emmanuel OO. NAD+ supplementation for anti-aging and wellness: A PRISMA-guided systematic review of preclinical and clinical evidence. Ageing Res Rev. 2026. PMID 41655607. https://pubmed.ncbi.nlm.nih.gov/41655607/
3. Gindri IM, et al. Evaluation of safety and effectiveness of NAD in different clinical conditions: a systematic review. Am J Physiol Endocrinol Metab. 2024. PMID 37971292. https://pubmed.ncbi.nlm.nih.gov/37971292/
4. Yoshino M, et al. Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women. Science. 2021. PMID 33888596. https://pubmed.ncbi.nlm.nih.gov/33888596/
5. Grant R, et al. A Pilot Study Investigating Changes in the Human Plasma and Urine NAD+ Metabolome During a 6 Hour Intravenous Infusion of NAD+. Front Aging Neurosci. 2019. PMID 31572171. https://pubmed.ncbi.nlm.nih.gov/31572171/
6. U.S. FDA. Compounding and the FDA: Questions and Answers. https://www.fda.gov/drugs/human-drug-compounding/compounding-and-fda-questions-and-answers
7. National Institute on Aging (NIH). What Do We Know About Healthy Aging? https://www.nia.nih.gov/health/healthy-aging/what-do-we-know-about-healthy-aging

Educational disclaimer

This article is for educational purposes only and is not medical advice, diagnosis, or treatment. It doesn't establish a doctor-patient relationship or confirm that you are a candidate for any therapy. Individual results vary, and no outcome is promised. Study figures are group results from the cited publications, not predictions for any individual. Compounded drugs are not FDA-approved, and FDA-approved brand products and compounded preparations are not interchangeable. Retatrutide is investigational. This article doesn't provide dosing or treatment protocols. Talk with a licensed clinician about your own situation. If you have a medical emergency, call 911.