What is NAD+?
The coenzyme behind cellular energy and DNA repair: what it is, why levels fall with age, and how physician-directed NAD+ therapy is delivered.
Quick answer
NAD+ (nicotinamide adenine dinucleotide) is a coenzyme found in every living cell, central to mitochondrial energy production, DNA repair, and hundreds of metabolic reactions. Research has documented that NAD+ levels decline with age in human tissue, and that this decline is associated with reduced cellular resilience. "NAD+ therapy" refers to physician-directed approaches that aim to help restore cellular NAD+ availability, most commonly, at ElevateMD, an at-home subcutaneous (SubQ) injection prescribed and monitored by a licensed physician. NAD+ used this way is a compounded, physician-prescribed medication, dispensed by a licensed pharmacy only after a physician reviews your health history. NAD+ may support general wellness and cellular-health goals rather than treat any specific condition, and individual results vary.
What is NAD+?
NAD+ is a coenzyme, a small helper molecule that other molecules need in order to do their job, present in every living cell in your body. Its full chemical name is nicotinamide adenine dinucleotide. If you picture the cell as a tiny factory, NAD+ is one of the most heavily used pieces of equipment on the floor: hundreds of separate reactions cannot run without it.
NAD+ cycles between two forms, an oxidized form (NAD+) and a reduced form (NADH), and that cycling is how cells move energy around. Because the molecule is constantly used up and remade, the body keeps producing it, from scratch and by recycling vitamin B3 family precursors. Which precursors feed that pathway is also the heart of the NAD+ vs NMN vs NR supplement question many people ask first.
What does NAD+ do in the cell?
NAD+ sits at the center of several core jobs:
- Energy production. NAD+ shuttles electrons through the mitochondria, the cell's power plants, to help turn food into usable cellular energy (ATP). This is why NAD+ is so often discussed in the context of energy and fatigue.
- DNA repair. Enzymes that repair damaged DNA (such as PARPs) consume NAD+ as they work. When repair demand is high, NAD+ is spent.
- Cellular signaling and maintenance. A family of enzymes called sirtuins depends on NAD+ to regulate processes tied to cellular stress responses and metabolic housekeeping [1][3].
- Hundreds of metabolic reactions. Beyond the marquee roles above, NAD+ is a required cofactor across a wide web of everyday metabolism.
The short version: NAD+ is less a single "function" and more a shared currency that many cellular processes spend, which is why interest in it has grown in longevity medicine, and why people also ask about the cognitive side, framed as NAD+ and brain fog or mental clarity.
Why do NAD+ levels decline with age?
This is one of the better-documented observations in the field. Studies measuring human tissue have found that NAD+ levels are lower in older people than in younger people, and that this decline tracks with rising oxidative stress [2]. Reviews of NAD+ metabolism describe the same broad pattern: availability falls over the lifespan, and that drop is associated with reduced cellular resilience [1].
Several mechanisms are proposed, increased consumption by repair and inflammatory pathways, reduced synthesis, and shifts in the recycling enzymes, but the full picture is still being worked out. What the evidence supports is the association between lower NAD+ and aging tissue. What it does not yet establish, in large human trials, is that raising NAD+ changes the trajectory of aging itself. That distinction matters, and any source that blurs it is overstating the science.
What is "NAD+ therapy" or "NAD+ optimization"?
"NAD+ therapy" and "NAD+ optimization" are umbrella terms for physician-directed approaches that aim to help restore cellular NAD+ availability, usually by administering NAD+ itself or a precursor under medical guidance. In a longevity-medicine practice, this is not an over-the-counter purchase: it is a prescribed, individualized protocol with ongoing oversight.
It is worth being precise about goals. NAD+ used in therapy is studied and offered in the context of general wellness, energy, and cellular-health goals. It is not a treatment for fatigue, aging, or any named medical condition, and outcomes differ from person to person. NAD+ used in therapy is a compounded, physician-prescribed medication, dispensed by a licensed pharmacy only after a physician has reviewed your health history.
How is NAD+ given? Routes of administration
There are two routes people most often compare:
- At-home subcutaneous (SubQ) injection, a small shot into the fatty tissue just under the skin, self-administered after a physician's instruction. This is ElevateMD's physician-directed approach. It takes minutes and fits into a normal day.
- In-clinic intravenous (IV) NAD+, given through an IV line during a drip-clinic appointment that can run from one to several hours of chair time.
Both routes deliver the same compound; the meaningful differences are practical, access, cost, convenience, and continuity of care, not a claim that one "works better," since large head-to-head trials comparing the routes have not been established. For the full breakdown, see NAD+ injections vs intravenous NAD+ and the walk-through of how at-home NAD+ injections are done. NAD+ is always subcutaneous in ElevateMD's service; intravenous administration is referenced here only as the in-clinic comparison.
Who is NAD+ for, and what does the evidence say?
NAD+ optimization tends to attract adults focused on longevity, daily energy, and general cellular health who want a physician-directed plan rather than a guess-and-check supplement routine. Whether it is appropriate for any specific person is a clinical decision a physician makes after reviewing health history. On the evidence, here is the honest frame:
- What is reasonably well supported: NAD+ is essential to core cellular processes, and its levels decline with age in human tissue [1][2].
- What is promising but earlier-stage: much of the strongest data on raising NAD+ is preclinical or early human work, and reviews describe the therapeutic potential as still being established [3].
- What is NOT established: NAD+ is not a treatment for any disease, it has not been shown to change how a person ages, and individual results vary.
That measured posture is deliberate. A practice that overpromises here is one to be skeptical of.
How physician-directed at-home NAD+ works
ElevateMD is a LegitScript-certified (#49567122) telehealth longevity practice. The path is physician-directed from the first step:
- Complete a short online assessment about your goals and health history (about 60 seconds to begin).
- A licensed ElevateMD physician reviews your information and any relevant labs, and confirms eligibility for your state.
- If clinically appropriate, a personalized NAD+ protocol is prescribed and the compounded medication is shipped from a licensed pharmacy to your home.
- Ongoing physician oversight keeps your plan titrated to you over time, with follow-up labs when appropriate.
From there, the common follow-on questions each have a dedicated guide: how much NAD+ therapy costs, NAD+ side effects and safety, how NAD+ dosage is set, and how to get NAD+ prescribed online. NAD+ care through ElevateMD is available to patients in the states where our physicians are licensed; eligibility is confirmed during the assessment.
Frequently asked questions
What is NAD+ in simple terms?
NAD+ (nicotinamide adenine dinucleotide) is a coenzyme found in every living cell. It acts as a shared helper molecule that many cellular processes, energy production, DNA repair, and hundreds of metabolic reactions, depend on to function. Its levels decline with age in human tissue.
What does NAD+ do in the body?
NAD+ helps the mitochondria turn food into usable cellular energy, supports DNA-repair enzymes, and is required by sirtuin enzymes involved in cellular maintenance and stress responses. It is best thought of as a currency that many processes spend, not a single function. Individual results vary.
Is NAD+ therapy a treatment for aging or any disease?
No. NAD+ levels decline with age, and research is studying NAD+ in the context of cellular health and longevity, but NAD+ is not a treatment for aging or any named medical condition, and it has not been shown to change how a person ages. It may support general wellness and cellular-health goals, and individual results vary.
Is NAD+ a medication or a supplement?
It can be either, depending on the form. Oral NAD+ precursors such as NMN and NR are sold as supplements. The NAD+ used in physician-directed therapy at ElevateMD is a compounded, physician-prescribed medication, dispensed by a licensed pharmacy only after a physician reviews your health history and used under ongoing oversight.
How is NAD+ given?
The two routes people compare are an at-home subcutaneous (SubQ) injection, self-administered after a physician's instruction, and an in-clinic intravenous (IV) session at a drip clinic. ElevateMD's service is the at-home subcutaneous route. Both deliver the same compound; the differences are practical, not a claim that one route produces different results.
How do I get started with physician-directed NAD+?
Complete ElevateMD's short online assessment, have a licensed physician review your goals and health history, and if it is clinically appropriate, your personalized protocol is prescribed and shipped to your home. Eligibility depends on the state where you live and is confirmed during the assessment.
See if physician-directed NAD+ fits your goals
You now have the physician's-eye view of what NAD+ is, what it does, and what the evidence does and does not say. The next step is personal: whether NAD+ is appropriate for you is a clinical question. Take the free 60-second ElevateMD assessment, and a licensed physician reviews your goals and health history, if NAD+ is clinically appropriate, your personalized, physician-directed plan ships to your door.
Start your free 60-second assessment →
ElevateMD is a LegitScript-certified telehealth longevity practice. NAD+ is a compounded medication prescribed only after physician review. This page is educational and is not individualized medical advice. Individual results vary.
References (primary sources)
- Covarrubias AJ, Perrone R, Grozio A, Verdin E. NAD+ metabolism and its roles in cellular processes during ageing. Nature Reviews Molecular Cell Biology. 2021;22(2):119-141. (PubMed)
- Massudi H, Grant R, Braidy N, Guest J, Farnsworth B, Guillemin GJ. Age-associated changes in oxidative stress and NAD+ metabolism in human tissue. PLoS One. 2012;7(7):e42357. (PubMed)
- Rajman L, Chwalek K, Sinclair DA. Therapeutic Potential of NAD-Boosting Molecules: The In Vivo Evidence. Cell Metabolism. 2018;27(3):529-547. (PubMed)
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