Disclaimer: The medications discussed in this article may include compounded preparations from a licensed 503A compounding pharmacy. Compounded medications have not been reviewed or approved by the FDA and are not the same as commercially available FDA-approved products. This content is for educational purposes only and does not constitute medical advice or establish a provider-patient relationship. Please consult a licensed healthcare provider for personalized clinical guidance.
NAD+ injections are subcutaneous injections of nicotinamide adenine dinucleotide, the coenzyme itself, prepared by a compounding pharmacy and self-administered at home. That one sentence separates them from nearly everything else sold under the NAD name, because the supplement market sells precursors, molecules the body converts into NAD+, while an injection delivers the finished product. Whether that distinction matters, and what the research says about each, is the subject of this article.
What NAD+ Is
Nicotinamide adenine dinucleotide is present in every living cell. It cycles between two forms, NAD+ and NADH, and that cycling is how cells move electrons during energy production. Without it, mitochondria cannot convert food into usable energy. NAD+ is also consumed by enzymes involved in DNA repair, cellular stress response, and circadian regulation, which is where the longevity interest comes from.
Levels decline with age. That decline is well documented in tissue studies, and it is the basis for the entire NAD+ market.
Precursors Versus the Molecule Itself
Oral supplements use precursors because NAD+ itself is a large, charged molecule that does not survive digestion or cross cell membranes efficiently. The two dominant precursors are nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN).
Both have human data. A 2016 study in Nature Communications showed that single oral doses of NR raised blood NAD+ in a dose-dependent manner, with the largest dose producing increases of up to 2.7-fold.[1] A 2017 pharmacokinetic study of eight healthy volunteers found that oral NR doubled whole-blood NAD+ at steady state, with no adverse events.[2] For NMN, a 2021 randomized trial in Science found that 10 weeks of supplementation increased muscle insulin sensitivity in postmenopausal women with prediabetes.[3]
So precursors work in the sense that they raise NAD+ in blood. The question is how much of that reaches tissue, and how it compares with delivering the molecule directly.
What an Injection Changes
A subcutaneous NAD+ injection bypasses digestion and the liver’s first pass, placing the coenzyme into the tissue beneath the skin, from which it is absorbed into circulation over hours. The appeal is directness: no conversion step, no dependence on gut absorption, and a sustained release rather than the brief spike of an IV drip.
The limitation is evidence. The precursor trials above are the strongest human data in the field. Direct NAD+ administration, whether IV or subcutaneous, has far less controlled research behind it in healthy adults. The mechanism argument for injection is sound. The trial base is thinner than for NR and NMN, and anyone who tells you otherwise has not read it.
Injection Versus IV
NAD+ IV infusions are the clinic version of the same idea, delivered over several hours because rapid infusion causes flushing, chest tightness, and nausea. A session typically costs several hundred dollars and requires a chair and a nurse.
Subcutaneous injection delivers a smaller amount more slowly, produces a lower peak with fewer infusion-related symptoms, and can be repeated on a schedule at home. The practical difference is consistency: an injection program is something people continue, and an IV program is something people do a few times and stop. For a molecule whose levels fall back when supplementation stops, consistency is the variable that matters.
What to Expect
Patients in our program report the first-month experience as subtle. Some notice steadier daytime energy and better sleep onset; some notice little. Injection-site redness and mild nausea shortly after injecting are the common side effects. The large, immediate felt effects described in IV lounge marketing are not what a subcutaneous program produces, and we tell people that before they start.
NAD+ injections are a reasonable choice for someone who has decided to raise NAD+ and wants the direct molecule on a sustainable schedule. They are not a substitute for the fundamentals that also raise NAD+: exercise, sleep, and not drinking heavily.
To see how our program is structured and priced, visit our NAD+ therapy page. For a comparison of the precursors, read our article on NAD+ versus NMN versus NR.
References
Trammell SA, Schmidt MS, Weidemann BJ, et al. Nicotinamide riboside is uniquely and orally bioavailable in mice and humans. Nat Commun. 2016;7:12948. PubMed: 27721479
Airhart SE, Shireman LM, Risler LJ, et al. An open-label, non-randomized study of the pharmacokinetics of the nutritional supplement nicotinamide riboside (NR) and its effects on blood NAD+ levels in healthy volunteers. PLoS One. 2017;12(12):e0186459. PubMed: 29211728
Yoshino M, Yoshino J, Kayser BD, et al. Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women. Science. 2021;372(6547):1224-1229. PubMed: 33888596
This article is for educational purposes only and does not constitute medical advice or establish a provider-patient relationship. Please consult a licensed healthcare provider for personalized guidance.
JP Rius is the founder of Precision Telemed. His perspective is shaped by the commercial, regulatory, and operational side of telehealth medicine.
