NAD+ infusion

What it is

NAD+ stands for nicotinamide adenine dinucleotide. The molecule is present in every cell and serves as a helper to enzymes that control energy metabolism, DNA repair and immune functions. The body builds it itself, among other things from precursors such as nicotinamide, nicotinamide riboside or NMN.

For the infusion, NAD+ is diluted in saline and given through a vein, usually over one to several hours. Practices also offer injections under the skin or into the muscle. The idea: to cut out the detour via the gut and raise the NAD+ level directly. The oral precursors NMN, nicotinamide riboside and NMNH are topics of their own and are mentioned here only for comparison.

The basic idea is understandable. NAD+ declines with age, and in animal studies raising it often improved metabolism, mitochondrial function, inflammation markers and performance. This is how a 2026 systematic review that included 80 rodent studies summarizes it.

How it is supposed to work

NAD+ is both helper and consumable. The sirtuins, which are involved in regulating genes, and the repair enzymes of the PARP family consume it in their work. If demand rises or new synthesis drops, supply from outside is supposed to close the gap.

The sticking point is the route into the cell. The pilot study by Grant et al. found that infused NAD+ disappeared completely from blood plasma in the first 2 hours without the level rising. The pattern of breakdown products fitted enzymes that cleave NAD+ outside the cells. Whether the cells reassemble the fragments into NAD+ and how much of it reaches muscle, heart or brain has not been measured in humans.

A finding from the randomized comparison by Hawkins et al. fits with this: in whole blood, NAD+ rose after the NAD+ infusion only after 24 hours, by 2 percent on average. Nicotinamide riboside through the vein raised the level faster, by 20.7 percent at peak. However, the study was paid for by the manufacturer of the nicotinamide riboside.

What the studies show

Grant et al., Front Aging Neurosci 2019

The first study to track what happens to infused NAD+ in humans. 11 healthy men aged 30 to 55, 8 of them with NAD+ over 6 hours and 3 with saline. In the first 2 hours, NAD+ in plasma did not rise; it was cleared completely. Only afterwards did NAD+ and its breakdown products rise, and NAD+ and methylnicotinamide appeared in the urine. No side effects were observed with the slow administration. The study was funded in part by a company whose director also runs a clinic that offers NAD+ infusions.

Hawkins et al., preprint 2024

Randomized, double-blind, placebo-controlled pilot study in healthy adults. Compared were a single infusion of NAD+, a single infusion of nicotinamide riboside, nicotinamide riboside taken orally and saline; 37 and 16 participants were analyzed in two parts of the study. In the second part, the tolerable NAD+ infusion lasted 98.88 minutes on average, the one with nicotinamide riboside 24.75 minutes. Under NAD+, participants described chest tightness, hot flushes, nausea and abdominal cramps. 3 hours after the infusion, neutrophils were higher than after nicotinamide riboside, which the authors interpret as an inflammatory reaction. The paper has not been peer-reviewed.

Reyna et al., Front Aging 2026

Retrospective analysis of client records of a US wellness provider, written by researchers working there. 6 clients received NAD+ through the vein on 4 consecutive days, 8 received nicotinamide riboside, follow-up 30 days. All 6 in the NAD+ group had moderate to severe complaints during the infusion, including abdominal cramps, nausea, vomiting, racing heart and chest pressure, which stopped when the infusion ended. The infusions lasted 97 versus 37 minutes on average. ALT, AST, CRP, kidney values and TSH did not change meaningfully; alkaline phosphatase fell in the NAD+ group but remained within the normal range, and HDL cholesterol fell.

Yu et al., Am J Cardiovasc Drugs 2026

Randomized, placebo-controlled single-center study in China with 180 adults with heart failure after ischemic cardiomyopathy. In addition to standard therapy, they received NAD+ through the vein or placebo for 7 days, at a study dose considerably lower than in the other studies mentioned here. The primary endpoint was the left ventricular ejection fraction after 1 month; it was 45.44 versus 42.44 percent and had thus improved more, p = 0.024. Major cardiac and cerebrovascular events over 6 months occurred in 14.6 versus 24.7 percent, not statistically significant. The manufacturer of the preparation supported the study.

Where the data stop

For what NAD+ infusions are mainly offered for, namely more energy, a clearer head, better recovery and slower aging, there is no controlled study. The systematic review by Gallagher and Emmanuel screened papers from 2010 to October 2025 and found 33 intervention studies in humans, but not a single one that tested NAD+ through a vein or muscle on aging or wellness endpoints. For use in addiction withdrawal, too, we found no controlled study.

The existing studies are small, short and mostly paid for by providers or manufacturers. The randomized comparison is available only as a preprint, and the client analysis has 14 participants and no placebo group. The heart study ran at a single center, with a low dose and an endpoint from cardiac ultrasound; major events and hospital stays were less frequent, but not significantly so. The basic question of how much of the infused NAD+ reaches the target cells also remains open. A 2026 case report describes a woman with rheumatoid arthritis whose complaints subsided after NAD+ infusions; the authors themselves stress that no cause-and-effect conclusion can be drawn from this.

Status, approval and legal

In the EU, there is no centrally approved NAD+ medicinal product; the medicines database of the European Medicines Agency lists no preparation with this active substance. The infusion is offered in medical practices and longevity centers; there is no approved indication. In the USA, NAD+ is likewise not an approved drug; the FDA lists it in its list for pharmacy compounding (as of May 14, 2026) in category 1, i.e. as a substance whose evaluation is still ongoing. In China, NAD+ for injection is registered as a medicinal product; the heart study used such a preparation. Important for competitive athletes: regardless of the active substance, the 2026 WADA Prohibited List bans intravenous infusions or injections of more than 100 milliliters within 12 hours, except in the context of hospital treatment, surgery or clinical diagnostics. We do not give dosages for use.

Safety

The typical complaints occur during the infusion and are well documented: pressure or tightness in the chest, nausea, abdominal cramps, diarrhea, feeling hot and racing heart. In the client analysis by Reyna et al., this affected all 6 NAD+ recipients in moderate to severe form; the complaints stopped when the infusion ended, and the infusions took longer because the rate was reduced. Users consistently report that slower dripping helps; that is experience, not a study. In the Grant study with administration over 6 hours, no side effects occurred. After the NAD+ infusion in the study by Hawkins et al., neutrophils rose, an indication of an inflammatory reaction. For injections under the skin or into the muscle, there is only a small manufacturer study as a preprint with 45 participants, in which 4 to 6 people each received NAD+ by different routes; no concerning signals were found, but this is not robust. Safety data over more than a few months or over repeated courses are lacking, as are data for pregnant and breastfeeding women.

Sources

• Grant et al., Front Aging Neurosci 2019 – NAD+ in plasma and urine during a 6-hour infusion
• Hawkins et al., medRxiv 2024 (preprint) – NAD+ and nicotinamide riboside through the vein in a randomized comparison
• Reyna et al., Front Aging 2026 – tolerability of NAD+ and nicotinamide riboside as an infusion, client analysis
• Yu et al., Am J Cardiovasc Drugs 2026 – NAD+ in heart failure, randomized study
• Gallagher and Emmanuel, Ageing Res Rev 2026 – systematic review of NAD+ for anti-aging
• Nkrumah-Elie et al., medRxiv 2026 (preprint) – safety of injections with NR and NAD+
• Itani et al., ACR Open Rheumatol 2026 – case report, rheumatoid arthritis
• FDA – Bulk Drug Substances Nominated for Use in Compounding (as of May 2026)
• NADA – WADA Prohibited List 2026, informational translation