NAD IV infusion—Is it really faster than taking it orally? — NMN vs. NAD injections by the numbers

💡 The key points first

· NAD (coenzyme I) is an essential coenzyme responsible for energy metabolism, DNA repair, and aging regulation in cells throughout the body, and when comparing people in their 20s and 50s, its level in the body drops to nearly half.

· If NAD is lacking, the activity of sirtuins (aging-regulating proteins) and PARP (DNA repair enzymes) slows down, leading to collagen breakdown and then fine lines and reduced elasticity.

· Of the three supplementation routes, the one with the most human evidence is oral NMN intake. In a study in which participants took 250 mg per day for 12 weeks, blood NAD levels increased significantly (Igarashi et al., 2022).

· The widely known NAD IV infusion shows a smaller-than-expected increase in blood NAD even when administered intravenously, and discomfort during administration is common, so debate over its efficiency continues.

· Lifestyle habits such as exercise, sleep, and sun protection are also the most undervalued ways to preserve NAD, and they directly contribute.

Often mentioned in the anti-aging field by the nickname "the switch of aging," NAD (NAD+, Nicotinamide Adenine Dinucleotide, coenzyme I) is in fact an ordinary coenzyme (an auxiliary substance that helps enzymes) present in every living cell. However, as interest has recently centered on NMN supplements and NAD IV infusions, the criteria for what should actually be chosen have become blurred by mixed information. In this article, we will look at why NAD is important for skin aging and compare three management methods based on the research evidence available so far.

How are skin aging and NAD connected?

The reason NAD is important does not end with its role in producing energy. That is because both of the two types of enzymes that directly regulate aging use NAD as fuel.

One is sirtuin. Sirtuins such as SIRT1 and SIRT6 are "NAD-dependent proteins" and only begin to function when NAD is present. They suppress the enzyme that breaks down collagen (MMP-1), protecting collagen, which is the basis of skin elasticity, and they also reduce inflammatory signaling (NF-κB).

The other is the PARP family of DNA repair enzymes. Skin suffers DNA damage every day from ultraviolet rays, air pollution, and oxidative stress, and PARP repairs this damage right away. The problem is that PARP also consumes NAD every time it works, so when NAD is insufficient, repair slows and damage accumulates.

But NAD declines with age. Multiple studies report that in humans, intracellular NAD drops to about half between the 20s and 50s. When NAD decreases, sirtuin activity falls and DNA repair slows, and as a result, senescent cells accumulate and chronic inflammation ("inflammaging") progresses. Furthermore, when inflammation occurs, an enzyme called CD38 consumes NAD even faster, creating a vicious cycle of 'NAD decline → inflammation → further NAD decline' (summary of a 2025 review by Nadis Academy). This is why attention is shifting toward NAD supplementation, since skin-care cosmetics alone have difficulty addressing intracellular energy and repair problems.

Management method 1 — Oral NMN: the choice with the strongest evidence

NMN (nicotinamide mononucleotide) is the immediate precursor of NAD and the material the body converts into NAD. Among the three management methods, it has the most clinical evidence in humans.

• In a randomized, double-blind trial in healthy older men, taking NMN 250 mg/day for 6 to 12 weeks significantly increased blood NAD and its metabolites, and improvements were observed in some measures of walking speed and grip strength (Igarashi et al., 2022, npj Aging).
• In a human comparative study published in Nature Metabolism in 2025, taking NMN and NR (another precursor) for 14 days increased blood NAD by about twofold, whereas ordinary nicotinamide did not produce the same effect (Christen et al., 2025).
• In terms of safety as well, a randomized, placebo-controlled trial in healthy adults that administered NMN 1,250 mg/day for 4 weeks reported no serious adverse events (2022).

That said, there are limitations that should be stated honestly. Large clinical trials directly measuring the skin-improving effects of NMN are still lacking, and current evidence combines the fact that it raises blood NAD with inferences through the sirtuin and PARP mechanisms described above. In addition, a meta-analysis combining 8 RCTs found that improvements in metabolic markers such as blood glucose and lipids were not statistically clear in healthy adults (2024). In other words, NMN is a "proven tool for reliably replenishing NAD," but the perceived effects vary greatly from person to person.

Management method 2 — NAD IV infusion: the gap between popularity and evidence

NAD IV infusion became popular mainly in wellness clinics with the concept of directly infusing it into a vein to replenish it quickly. Intuitively, it seems the strongest, but recent human studies show that it is not as simple as expected.

The NAD molecule is large, making it difficult to enter cells directly. In one comparative human study, NAD IV infusion increased blood NAD by only about 2% after 24 hours, while NR IV infusion increased it by about 20% in just 3 hours (2026, retrospective pilot study). In the NAD IV group, changes in indicators suggesting an inflammatory response, such as increased white blood cells and neutrophils, were also observed.

In terms of how it feels, NAD IV infusion often causes discomfort such as burning, nausea, and chest pressure if infused too quickly, so it has to be given slowly (usually over tens of minutes to several hours). The U.S. FDA has warned about contamination and quality risks in some compounded NAD injectable products. A 2020 systematic review summarized that randomized trials of NAD infusion therapy are few and that the evidence is "promising but still preliminary."

In summary, NAD IV infusion may be considered if rapid replenishment is desired or if oral absorption is difficult, but the common belief that "intravenous means it is always more efficient" is not supported by current evidence. For skin aesthetics and anti-aging purposes, it is advisable to make a decision only after being fully informed about the expected effects, discomfort during infusion, and the evidence relative to cost.

Management method 3 — Lifestyle habits: the most undervalued NAD management

Before supplements or injections, there are lifestyle habits that help the body use less NAD and produce more of it. Regular aerobic exercise stimulates the NAD synthesis pathway, and sufficient sleep and fasting (including intermittent fasting) are reported to work in ways that reduce NAD consumption. Above all, sun protection is the most cost-effective "NAD-saving" method because it reduces DNA damage itself, which PARP would otherwise have to repair.

Diorre clinical principles

In our clinic, we guide NAD management not as something that ends with a single procedure, but as something that is built up in order of evidence strength. First we check the foundations such as sun protection, sleep, and exercise; then we add the oral precursors with the strongest evidence (NMN/NR); and only when rapid replenishment is needed or oral use is difficult do we present IV infusion as an option after fully explaining expectations and limitations. Because NAD management is an area where perceived differences can be large, our principle is to guide patients without exaggeration and within the current evidence.

What foreign patients consulting in Gangnam often ask along with NAD injections

Q. Can I receive an NAD injection and Rejuran at the same visit?

The two work in completely different ways. NAD is a systemic supplement that helps whole-body cellular energy metabolism and DNA repair, while Rejuran (PDRN/PN ingredients) is a local procedure injected directly into the dermis to stimulate hydration and collagen synthesis. Since the two do not overlap, they are often scheduled on the same day, but the order and interval should be decided after consulting the medical staff according to each person's skin and health condition.

Q. Can NAD injections help with recovery before or after lifting procedures such as Thermage or Sofwave?

Thermage (RF) and Sofwave (HIFU) are procedures that apply heat stimulation to the deeper layers of the skin to induce collagen remodeling, and during this process cells use more energy and DNA repair resources than usual. It is mechanistically plausible that NAD serves as fuel for this process, but there is still no direct clinical comparison proving that "NAD injections speed recovery after lifting procedures." The principle is to explain expectations and evidence separately.

Q. I am a foreign patient coming to Gangnam for ReTUO or Ulthera; can I get an NAD injection on the same day?

In most cases, NAD IV infusion can be coordinated within the same-day schedule together with a collagen booster (ReTUO) or ultrasound lifting (Ulthera). However, because NAD infusion must be administered slowly and the order may need to be adjusted depending on each individual's condition, we recommend planning the overall schedule and sequence together during the pre-visit consultation.

Frequently asked questions

Q1. How much NMN supplement should I take per day to raise NAD?

In human studies, blood NAD increased significantly when 250 mg/day was taken for 6 to 12 weeks, and reports have shown that even up to 1,250 mg/day was used safely for 4 weeks. There is still insufficient evidence that higher doses proportionally increase the effect, so in general, consistent use is more important than short-term high-dose use. Please consult a clinician about any underlying conditions or medications before taking it.

Q2. Is NAD IV infusion faster and better than taking NMN orally?

Contrary to intuition, in human studies NAD IV infusion produced a limited rise in blood NAD even after administration (about 2% after 24 hours), whereas precursor (NR) IV infusion increased it by about 20% in just 3 hours. This is because the NAD molecule is difficult to enter cells directly. It cannot be considered unconditionally superior simply because it is given intravenously.

Q3. Does NAD infusion improve wrinkles or elasticity?

Mechanistically, it is clear that NAD is involved in protecting collagen and DNA repair through sirtuins and PARP, but skin clinical studies directly proving that NAD injections improve wrinkles or elasticity are currently very limited. For aesthetic purposes, it is better to understand the difference between mechanistic expectations and actual evidence.

Q4. Which is better, NMN or NR?

Both ingredients have a human comparative study showing that 14 days of use increased blood NAD by about twofold, so their efficiency in raising NAD is considered similar (Christen et al., 2025). There are also data showing that NR raised NAD faster when given intravenously. Rather than one being absolutely superior, the choice depends on the form of absorption and individual response.

Q5. Is it normal to feel nauseous or chest tightness during NAD infusion?

When infused quickly, burning, nausea, and chest pressure are commonly reported, which is why slow infusion is standard. However, if the symptoms are severe or persistent, you should inform the medical staff immediately.

Closing

NAD is a key coenzyme that connects aging and skin at the cellular level, and the fact that it declines with age is clear. However, what to use to replenish it should be judged not by marketing but by the strength of the evidence. So far, lifestyle habits and oral precursors (NMN/NR) are the most proven foundation, and for IV infusion it is best to choose it only after being accurately informed about expectations and limitations. At Diorre Clinic, we look at each person's skin condition and lifestyle together when designing the order of management.

ℹ️ This content is intended to provide general medical information and does not replace individual consultation. The indications and precautions for taking supplements such as NMN and for IV infusions may vary depending on each person's health condition, and accurate diagnosis and consultation should be conducted with a skin-aesthetic medical professional.