NAD+ injections vs. IV infusions: what the evidence actually shows

What did @wwaclinic actually say?

A board-certified nurse practitioner introduced NAD+ therapy as a new service at her clinic and listed several benefits: "DNA cellular repair," anti-aging, energy, brain fog, and muscle support. She also described NAD+ as "an enzyme that is found in everybody at the cell." The video is promotional in nature, meant to drive appointment bookings, which is worth keeping in mind when evaluating how the claims were framed.

To her credit, she kept things relatively brief and did not promise to cure any specific disease. The tone was enthusiastic but not wildly exaggerated by telehealth-content standards. Still, a couple of things she said need to be examined more carefully, because not everything she described is supported the way her confidence implied.

Does the science back this up?

Partially. NAD+ does play a real role in cellular metabolism and DNA repair pathways. The science here is not invented. But "does play a role" is doing a lot of work in that sentence, and the gap between biological function and clinical benefit in healthy humans is wide.

NAD+ is a coenzyme, not an enzyme, involved in redox reactions and as a substrate for enzymes like sirtuins and PARPs, which do participate in DNA repair signaling. Studies in older adults, like Yoshino et al. (2021, Science) on NMN supplementation, showed improvements in muscle insulin sensitivity, but that was oral supplementation in postmenopausal women, not injectable NAD+. Intramuscular and subcutaneous NAD+ delivery routes have almost no published randomized controlled trial data in healthy populations. Most of the human research that exists focuses on addiction treatment or acute neurological conditions, not the general wellness benefits being promoted here.

What did they get wrong (or right)?

The enzyme mistake is worth correcting directly. NAD+ is a coenzyme, a small molecule that assists enzymes. Calling it an enzyme is technically inaccurate, though it may sound like a small distinction. In a clinical setting, precision matters.

The claim that NAD+ therapy will help with "DNA cellular repair" is a stretch in a consumer context. Yes, NAD+ is a substrate for PARP enzymes that repair DNA strand breaks. But claiming injections translate to measurable DNA repair in a healthy person is not supported by clinical evidence. It is a mechanism extrapolated into a promise. Conze et al. (2019, Scientific Reports) found that NAD+ precursor supplementation raised blood NAD+ levels, but raising blood levels does not automatically mean downstream cellular repair is happening at a therapeutically meaningful rate.

The anti-aging framing, while popular, is also ahead of the evidence. Camacho-Pereira et al. (2016, Cell Metabolism) showed NAD+ decline with age in mice and that replenishment helped, but translating rodent longevity data to human anti-aging injections is a significant leap. Credit where it is due: she did not claim it would add years to your life or reverse a specific disease.

What should you actually know?

Injectable NAD+ is being offered widely in wellness clinics before the clinical evidence for healthy-population use has caught up. That does not mean it is dangerous, but it does mean the benefit-to-cost calculation is unclear. IV NAD+ infusions have more anecdotal clinical use history, particularly in addiction medicine. IM and subcutaneous routes are newer and even less studied in terms of bioavailability compared to IV delivery.

If you are considering NAD+ therapy, the honest conversation to have with a provider includes: what outcome are we actually measuring, what is the plan if nothing changes, and what does this cost over time. A 2023 review by Lautrup et al. in Cell Metabolism acknowledged that while NAD+ biology is compelling, "the translation to clinical interventions in humans remains in early stages." That is a fair summary of where things stand. Enthusiasm from a clinic is not the same as evidence from a trial.