The Basics
What Is NAD+ and Why Does It Matter?
NAD+ (nicotinamide adenine dinucleotide) is a coenzyme found in every living cell. It sits at the center of how your body turns food into usable energy and how cells repair and maintain themselves. Without adequate NAD+, the mitochondria that power your cells cannot work as efficiently.
Here is the catch: NAD+ levels tend to decline with age. In human skin samples, NAD+ fell steadily from infancy to old age (Massudi et al., 2012). That decline has made NAD+ one of the most discussed molecules in longevity and health-optimization medicine.
At Protocol Health in Scarsdale, NY, we approach NAD+ the way we approach everything: as a physician-supervised, individualized therapy informed by your goals and, where appropriate, your labs. This article is educational and is not medical advice; suitability is always determined case by case with a qualified provider.
Explore NAD+ Therapy at Protocol HealthQuick Answer
What Does NAD+ Therapy Do, in Plain Terms?
NAD+ therapy aims to replenish a coenzyme your body depends on for energy production, DNA repair, and cellular resilience. People use it hoping to ease fatigue and brain fog and to support healthy aging, but human trials have not yet shown those benefits.
It is delivered most commonly as an IV infusion, and sometimes by injection, under clinical supervision. Human trials show NAD+ precursors raise NAD+ and are well tolerated, and one trial found better muscle insulin sensitivity. No trial has shown cognitive benefits, responses vary, and NAD+ is not a cure for any disease. Injectable and IV NAD+ are compounded preparations, and NAD+ is not FDA-approved for any use.
Protocol Health offers NAD+ as an injection, so we have a commercial interest in it.
The Mechanism
How Does NAD+ Work in the Body?
NAD+ works in the body through two main jobs. First, it acts as a shuttle in metabolism, carrying electrons through the reactions that convert food into ATP, your cells' energy currency. When NAD+ is abundant, that energy pipeline tends to run more smoothly.
Second, NAD+ is a required fuel for a family of repair and regulatory enzymes called sirtuins and PARPs. These proteins help maintain DNA, regulate inflammation, and manage how cells respond to stress. As NAD+ falls with age, these protective systems can lose efficiency.
An IV enters the bloodstream directly, and an injection is absorbed from under the skin or from muscle. Both avoid the gut, but no human trial shows that either raises NAD+ inside cells more than oral precursors, which raised blood NAD+ in a randomized trial (Martens et al., 2018). Infused NAD+ is also cleared from the blood quickly, through breakdown and/or tissue uptake.
The Upside
What Are the Benefits of NAD+?
Patients most often seek NAD+ for energy, mental clarity and a general sense of vitality; controlled human trials have not confirmed those benefits. Many people pursue NAD+ specifically for fatigue, brain fog, or the feeling of running on empty despite adequate sleep.
In the longevity and recovery context, NAD+ is studied for its role in mitochondrial function, cellular repair, and metabolic health. Some people use it as part of athletic recovery or after periods of high stress, illness, or intense training.
It is important to be honest here: these are reasons people try NAD+, not demonstrated results, and no outcome is guaranteed for anyone. We frame it as one option within a broader, lab-informed longevity plan rather than a standalone solution.
The Evidence
What Does Human Research Show About NAD+ Benefits?
Human research on NAD+ benefits shows that precursors can raise NAD+ and were well tolerated in short trials, while most of the dramatic benefits you read about come from animal studies. Human research is smaller, shorter and more cautious, and it is worth knowing exactly what it has shown.
Raising NAD+ in people is achievable. In a randomised, placebo-controlled crossover trial in Nature Communications, six weeks of the NAD+ precursor nicotinamide riboside was well tolerated and effectively stimulated NAD+ metabolism in healthy middle-aged and older adults. The authors flagged blood pressure and arterial stiffness as worth testing in larger trials, which is a hypothesis, not a result.
The clearest functional result so far is metabolic. In a 10-week randomised trial published in Science, the precursor nicotinamide mononucleotide (NMN) increased muscle insulin sensitivity and insulin signalling in postmenopausal women with prediabetes and overweight or obesity, while placebo did not.
Direct NAD+ infusions have been studied far less. A 2019 pilot study of a six-hour NAD+ infusion found the infused NAD+ was rapidly cleared from the blood for the first two hours, with breakdown products later appearing in the urine. That tells us how the body handles IV NAD+, not what it does for energy or aging.
Claims that NAD+ reverses aging, cures fatigue or sharpens cognition are ahead of the human evidence.
Delivery
NAD+ Injections vs IV vs Supplements: Do the Benefits Differ?
NAD+ is offered three ways, and the trade-offs are practical rather than proven differences in benefit. IV infusions deliver NAD+ directly into the bloodstream over an hour or more, which is why they are the most common clinic format and the one most associated with infusion-related nausea and chest tightness.
NAD+ injections deliver a smaller amount under the skin or into muscle in a few minutes, and the dose is absorbed from there rather than entering the bloodstream directly. Injections are more convenient for maintenance and do not carry the infusion-rate flush of an IV, though injection-site discomfort is common. Both injectable routes avoid the gut, but no human trial shows either raises NAD+ inside cells more than oral precursors.
Oral NAD+ supplements and precursors such as nicotinamide riboside and NMN are the best-studied route in clinical trials, because they are easiest to test. Product quality varies widely, however, and supplements are not regulated like prescription medications.
No head-to-head trial has shown that one route produces better long-term NAD+ benefits than another. The right choice depends on your goals, tolerance and budget, and is worth discussing with a clinician. Learn more about NAD+ therapy at Protocol Health.
Women and Men
NAD+ Benefits for Women and Men
NAD+ works the same way in women and men, and there is no strong evidence for sex-specific NAD+ benefits. Marketing that promises NAD+ for hormones, fertility or testosterone goes well beyond the data.
The one notable trial in women, the NMN study above, was in postmenopausal women with prediabetes, and it measured insulin sensitivity rather than energy or appearance. Most other human studies have enrolled mixed groups of middle-aged and older adults.
For both women and men, symptoms like fatigue and brain fog often have identifiable causes, including thyroid disease, low iron, poor sleep and shifting sex hormones. That is why our approach to fatigue, brain fog and low energy starts with a workup before recommending NAD+.
Is It For You?
Who Is a Good Candidate for NAD+ Therapy?
Good candidates for NAD+ therapy tend to be adults dealing with persistent fatigue, brain fog, and low energy, as well as those pursuing proactive longevity and preventive health. It is often considered alongside broader work like hormone optimization or metabolic health.
Candidacy is determined during a consultation. A provider will review your history, goals, medications, and relevant labs to decide whether NAD+ is appropriate and, if so, at what dose and cadence. Certain conditions and pregnancy warrant caution or may make it unsuitable.
If you are exploring NAD+ as part of a bigger picture, a comprehensive evaluation such as one of our longevity assessments can help clarify where it fits. The right starting point is a conversation with a clinician who can tailor the plan to you.
The Fine Print
Is NAD+ Safe, and What Are the Side Effects?
NAD+ safety depends on your history, but under clinical supervision it is generally well tolerated, and its most common side effects occur during the infusion itself. They include a flushing sensation, chest tightness, nausea, or lightheadedness if the drip runs too quickly.
These sensations are typically managed by slowing the infusion rate, which is one reason clinical supervision matters. It is also why we do not recommend unmonitored or at-home high-dose protocols.
NAD+ can interact with certain medications and conditions, so a thorough intake is essential. As always, this content is educational and is not a substitute for personalized medical advice from a qualified provider who knows your history.
The Experience
What Happens at a NAD+ Infusion Appointment?
A NAD+ infusion appointment is where a slow, monitored infusion happens after a consultation sets the dose and schedule. At clinics that offer NAD+, the first step is typically a consultation to confirm it is appropriate and to set a dose and schedule. Some people begin with a series of sessions, then move to periodic maintenance.
An IV infusion is administered slowly and can take from roughly 45 minutes to a few hours depending on the dose. The patient is seated and monitored, and the rate is adjusted to limit flushing and nausea.
Some people describe feeling clearer or more energized in the days after a session, while others notice little; these are personal reports, not trial results. The prescribing provider gauges the response and adjusts the plan over time.
The Protocol Health Way
How Does Protocol Health Approach NAD+?
Protocol Health approaches NAD+ as a family-owned, physician-led clinic in Scarsdale, NY, with consultations available by telehealth in New York, New Jersey, Connecticut, Florida and California. Every NAD+ plan is overseen by our clinical team and built around you.
Rather than treating NAD+ as a menu item, we position it within a lab-informed longevity strategy. That may mean pairing it with body composition, biological age, or hormone assessments so decisions are grounded in data, not guesswork.
The bottom line on NAD+ benefits: NAD+ falls with age and can be raised with precursors that were well tolerated in short trials, but the energy, clarity and anti-aging benefits people seek have not been shown in human trials. For why NAD+ declines with age, see NAD+ and aging. If you are curious whether NAD+ belongs in your plan, the best next step is a personalized consultation, starting with the Protocol Health Signature Health & Longevity Assessment. Our team will help you understand the options and design an approach that fits your goals and your physiology.
FAQ
Frequently Asked Questions
Is NAD+ a peptide or a vitamin?
NAD+ is neither, strictly speaking. It is a coenzyme derived from vitamin B3 (niacin) that every cell uses for energy metabolism and repair. It is often grouped with peptide and longevity therapies because of its role in cellular health and aging research.
What are the side effects of NAD+?
During IV infusions, the most common side effects are nausea, flushing, chest tightness and lightheadedness, which usually ease when the drip is slowed. Injections can cause local soreness. In a 2026 study comparing infusions, NAD+ IV caused more gastrointestinal symptoms and chest pressure than an IV precursor, and symptoms resolved once the infusion ended.
How long does NAD+ therapy take to work?
Responses vary widely. Some people report improved energy or clarity within a few days of a session and others notice little; no controlled trial has measured how quickly NAD+ therapy works. Your provider can help set realistic expectations based on your goals and health profile.
Are NAD+ supplements as good as NAD+ injections or IV?
No trial has compared their long-term benefits head to head. Oral precursors such as nicotinamide riboside and NMN are the best studied and do raise NAD+ levels, but supplement quality varies. An IV enters the bloodstream directly and an injection is absorbed from under the skin or muscle; no human trial shows either raises NAD+ inside cells more than oral precursors. A clinician can help you weigh the options.
What is the difference between NAD+ IV and NAD+ injections?
An IV infusion delivers a larger dose slowly and directly into the bloodstream, and its flush, nausea or chest tightness are rate effects that ease when the drip slows. An injection is a smaller dose absorbed from under the skin or from muscle, which some people use for maintenance. A clinician will recommend the right route for your situation.
Can I get NAD+ therapy through telehealth?
An initial consultation and parts of your broader longevity plan can often begin via telehealth in New York, New Jersey, Connecticut, Florida or California.
Does NAD+ reverse aging?
No responsible clinician will promise that. NAD+ is involved in cellular energy and repair processes that decline with age, and patients often seek it for healthy aging, but controlled human trials have not shown that NAD+ therapy slows or reverses aging. Research is ongoing.
How often should I get NAD+ infusions?
There is no universal schedule. Many people start with a short initial series and then move to periodic maintenance sessions. Frequency is set by the prescribing clinician based on response, goals, and labs.
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