What Is NAD+?

The Basics

NAD+ (nicotinamide adenine dinucleotide) is a coenzyme found in every cell in your body. Its core job is enabling cellular respiration — the process your cells use to convert the food you eat into usable energy (ATP).

Without adequate NAD+, your mitochondria — the energy-producing structures inside every cell — cannot function efficiently. The practical result is energy output that falls short of what your body actually needs, which most people experience simply as persistent, unexplained fatigue.

Beyond energy production, NAD+ plays two other critical roles:

DNA repair and gene expression. NAD+ activates a family of proteins called sirtuins, which regulate DNA repair, inflammation control, and how your cells respond to stress.

Metabolic regulation. NAD+ activates AMPK, an enzyme that functions as your cells' energy sensor — when properly activated, it promotes fat burning and discourages fat storage.

Why NAD+ Levels Decline

NAD+ levels decline naturally with age — research suggests a drop of as much as 50% between your 40s and 60s. But age isn't the only factor:

• Chronic stress draws heavily on NAD+ reserves through increased activity of PARP enzymes, which consume NAD+ during inflammatory responses
• Poor sleep disrupts the circadian-regulated processes involved in NAD+ synthesis
• Alcohol consumption actively depletes NAD+, as the liver prioritizes metabolizing ethanol over normal energy production
• Post-viral recovery has been linked to measurable drops in NAD+ availability
• Hormonal changes — specifically declining estrogen during perimenopause and menopause — accelerate NAD+ depletion in women beyond age-related decline alone

For people dealing with a combination of these factors, the cumulative NAD+ deficit can become significant enough that lifestyle changes alone — better sleep, improved diet — don't fully restore normal energy and function.

How NAD+ Therapy Restores It

Because NAD+ levels can be measurably depleted by all of the factors above, restoring them through supplementation has become a structured area of telehealth and wellness medicine. There are three primary delivery methods, each with significant differences in how much NAD+ actually reaches your cells:

Oral supplements (capsules, tablets, precursor compounds like NMN and NR) must survive digestion before any NAD+ becomes available — a process that destroys a significant portion of the dose before it ever reaches circulation.

Injectable NAD+ bypasses the digestive system entirely, delivering NAD+ directly into the bloodstream for much more reliable, predictable absorption. See our full dosage guide for typical dosing ranges and frequency.

IV NAD+ therapy delivers the highest concentration directly into a vein in a clinical setting, but requires in-person visits and carries a significantly higher cost.

Full breakdown of all three methods: see our delivery method comparison → For side effects and what to expect from injections, see our NAD+ injection side effects guide. Wondering how dosing translates day to day? See our dosage per day breakdown.

What NAD+ Therapy Is Used For

Restoring NAD+ levels through structured, medically supervised therapy is most commonly associated with:

• Energy and fatigue support — addressing the cellular energy deficit behind persistent tiredness
• Cognitive clarity — supporting the brain's unusually high energy demands and reducing brain fog
• Metabolic support — improving the cellular conditions that make healthy metabolism and weight management possible
• Healthy aging — supporting the DNA repair and cellular maintenance processes that slow with age

Full benefits breakdown: see how NAD+ injections can help →

Frequently Asked Questions