What are NAD+ injections and how do they work?

NAD+ injections are subcutaneous shots of nicotinamide adenine dinucleotide — a coenzyme every cell uses to produce energy and repair DNA. Under physician supervision, NAD+ injections are used to restore levels that decline with age, with the goal of supporting energy, mental clarity, recovery, and healthy aging. They are self-administered at home on a prescribed schedule, and dosing is individualized.

What NAD+ actually does in the body

NAD+ (nicotinamide adenine dinucleotide) is a coenzyme required for the mitochondria — the energy factories inside every cell — to convert food into usable ATP. It also activates sirtuins and PARPs, enzyme families involved in DNA repair, stress response, and metabolic regulation. When NAD+ is low, cellular energy production and repair both slow down.

NAD+ levels fall meaningfully with age, poor sleep, chronic stress, alcohol, and metabolic disease. Restoring NAD+ has become a focus of longevity medicine because it targets a mechanism upstream of many age-related declines rather than a single symptom.

Why injection instead of IV or oral

Oral NAD+ precursors (NR, NMN) raise NAD+ levels modestly and are taken daily. IV NAD+ delivers a large dose directly to the bloodstream but requires a clinic visit and several hours per session. Subcutaneous NAD+ injections sit in between: they deliver a meaningful dose you can self-administer at home on a physician-prescribed schedule, without the time cost of an IV.

For most patients on a physician-supervised protocol, subcutaneous injection is the most practical way to run a consistent NAD+ program over weeks or months.

What most people feel — and when

Reported effects vary. Many patients notice steadier energy, better mental clarity, and improved recovery within the first few weeks of consistent use. Sleep quality often improves in parallel. Longer-term benefits are the point of the protocol: NAD+ is a cellular-repair signal, and the meaningful effects build over months, not days.

NAD+ is not a stimulant. If you're expecting a coffee-like jolt, you'll be disappointed. What patients typically describe is 'less depleted' — fewer afternoon crashes, more capacity to recover from training or a hard week.

Common side effects and safety

The most common side effects are transient flushing, mild nausea, or a warm sensation shortly after injection — most people describe these as mild and improving as the body adjusts. Injection-site redness or itching can occur. Serious reactions are uncommon at physician-supervised doses.

NAD+ therapy is not appropriate for everyone. A prescribing physician screens for relevant conditions and interactions before starting a protocol and adjusts dosing based on how you respond. Compounded NAD+ is not FDA-approved.

Medically reviewed by Dr. Michael Mimlitz, MD (NPI 1508891870), Chief Physician of GOAL.MD. Physician-supervised telehealth. More at goal.md/answers.