NAD+: the complete guide.

The short version.

If you read nothing else, read this. The whole guide in a handful of bullets.

Quick reference.

What is NAD+?

NAD+ stands for nicotinamide adenine dinucleotide, which is a mouthful, so almost everyone just says NAD+. It is a coenzyme, a small helper molecule your cells already make and use constantly. It is not a peptide, but it gets discussed alongside peptides because it is run in the same injectable, research-use format and sits at the heart of the same longevity conversation.

Its job is to help run energy. NAD+ shuttles electrons inside your mitochondria, the tiny power plants in your cells, so they can produce ATP, the fuel that keeps everything working. It is also the currency that DNA-repair enzymes and a family of longevity-linked proteins called sirtuins have to spend in order to do their jobs.

Here is the part that drives all the interest: NAD+ levels fall as you age. By the time many people reach middle age, their levels are a fraction of what they were in youth. The idea behind supplementing it is simple, top the tank back up and give the cellular machinery more fuel to work with.

Worth saying plainly: the fact that NAD+ is essential to your cells is not in question. What is far less settled is whether injecting extra NAD+ produces meaningful anti-aging benefits in otherwise healthy people. The human evidence is still thin and early, and it is sold strictly for research use only. We get into what that means further down.

How it works in the body.

You do not need a biology degree to follow this. Here is the simple picture, then a little more for the curious.

The core idea is that NAD+ is a coenzyme, a molecule that other enzymes cannot work without. Refill it, and several different cellular systems that all depend on it have more to draw from. It shows up in three overlapping roles that come up again and again in the research.

• Energy production. NAD+ carries electrons through the reactions in your mitochondria that produce ATP. Without enough of it, the cell's energy assembly line slows down. This is the role most directly tied to the reports of steadier energy.
• DNA repair. The enzymes that find and fix damaged DNA, the PARP family, burn NAD+ as fuel. When NAD+ is plentiful, that repair work has the resources it needs, which is one reason the molecule is central to aging research.
• Sirtuin activation. Sirtuins are proteins tied to longevity and stress resistance, and they literally cannot function without NAD+. Keeping NAD+ topped up is what lets them regulate metabolism, repair, and the cellular stress response.

How to take it: routes of administration.

NAD+ is an injectable in the research-use world, but it is unusual in having a real clinical IV version and gentler oral precursors too. Here is the honest comparison of how people actually take it.

Where to inject.

If you go this route, these are the sites people use. Rotate so no single area gets sore.

The easiest spots are the belly (about 2 inches either side of the navel), the love handles, the front of the thigh, and the back of the upper arms. Rotate every injection.

So which should a beginner pick? For at-home use, subcutaneous is the answer: it is far more practical than sitting through an IV, and you control the pace and dose. IV is worth considering only through a clinic if you want the biggest single hit. Oral precursors are the lowest-effort option and a reasonable way to coast between injectable courses.

Reconstitution: mixing it.

NAD+ arrives as a dry powder, so before you can inject it you reconstitute it, which just means adding liquid to turn the powder into something you can draw into a syringe. It sounds technical but takes about a minute.

Once it is mixed, the only real question is how many units to draw. That depends on your vial size, your water amount, and your target dose, and it is easy to get wrong by hand.

• Use bacteriostatic water, often called BAC water. The small amount of preservative keeps the mixed vial usable for a couple of weeks.
• Add the water slowly, down the inside wall of the vial. A common mix is a 500 mg vial plus 3 mL of BAC water, which gives a concentration of about 167 mg/mL.
• Swirl, do not shake. Gently roll the vial until the powder dissolves. Shaking can damage the molecule and create foam.
• Store it in the fridge once mixed, keep it out of light, and use it within about two weeks.

Open the dosage calculator to turn your vial and dose into an exact number of units. As a worked example: a 500 mg vial mixed with 3 mL of BAC water gives about 167 mg/mL, so a 50 mg dose is 0.3 mL, which is about 30 units on a U-100 insulin syringe, and that vial holds around 10 doses at that size.

Dosing by goal.

There is no single official dose for NAD+, because the injectable form is not an approved medicine. What follows is the range people commonly run, organized by phase. The defining feature of NAD+ dosing is starting low and going slowly, because the side effects are dose- and speed-dependent.

Starting out

Most people begin around 50 mg, two to three times a week, and pay close attention to how the injection feels. Pushing the plunger slowly matters as much as the dose. The goal of the first couple of weeks is to find a dose and pace that do not leave you flushed or queasy.

Working dose

From there, people often build toward 100 mg per injection as tolerated, still two to three times a week. A commonly cited ceiling is to stay under roughly 300 mg total per week for subcutaneous use without further guidance.

Bridging with oral

Some people run an injectable course, then bridge with oral NMN or NR, around 250 to 500 mg daily, before starting another course. This keeps a steadier baseline without daily injections.

Cycling and timing.

A cycle just means a defined run of time on the compound, followed by a break. For NAD+ the common pattern is a course of roughly 8 to 12 weeks of injections, then either a break or a stretch of oral precursors, rather than injecting indefinitely.

Why not just run it forever? Mostly because the long-term human safety data on injectable NAD+ does not exist yet. The cautious and widely followed approach is to run a focused course, then ease off.

• Hold a steady schedule through your course, two to three times a week at roughly even spacing.
• Bridge rather than binge. If you want continuity, step down to oral NMN or NR between courses instead of pushing the injections higher.
• Take a real break after a course before starting another. If your goals or symptoms change, that is a conversation for a licensed provider.

Stacking NAD+.

NAD+ is often run alongside other longevity compounds rather than alone. It is the energy-and-repair currency that several of them lean on.

See full recipes, dosing, and how people run them on the stacks page.

Side effects and safety.

In the reports we see, NAD+ is generally described as tolerable, but it has a more noticeable acute reaction than most compounds here, driven by dose and injection speed. The ones people mention most often are:

• Flushing, a warm, tingling, sometimes intense feeling during or just after the injection, worse at higher doses and faster pushes.
• Nausea or queasiness, usually brief, again tied to going too fast or too high.
• Headache or lightheadedness, shortly after a dose in some people.
• Injection-site irritation, a little redness or a small bump, which is why rotating sites matters.

Who should be cautious.

Some people have clear reasons to be extra careful, or to avoid injectable NAD+ entirely until they have spoken with a licensed provider.

• Pregnant or breastfeeding. There is no safety data here, so this is a hard avoid.
• A history of cancer, or active cancer. NAD+ feeds DNA repair and metabolic pathways that some tumors also rely on, so caution is widely advised. This is a conversation for an oncologist, not a forum.
• Heart conditions or low blood pressure. The flushing reaction involves blood vessels, so anyone with cardiovascular concerns should be cautious and go slow.
• Anyone on other medications. If you take prescription drugs or manage a chronic condition, talk to your provider first.

And the universal one: whoever you are, talk to a licensed healthcare provider before starting NAD+. This guide is educational, not a substitute for personalized medical advice.

Where to buy it safely.

This is where a lot of beginners get burned, because peptide and research-compound quality varies wildly between vendors and the cheapest vial is not always the real deal. Our honest take: do not shop on price alone, shop on price plus independent lab data.

• Compare vendors side by side. Price ranges are wide, and the difference between the lowest and highest listing can be large for the exact same compound.
• Look for recent third-party lab tests. The gold standard the community looks for is a recent Janoshik certificate of analysis showing purity for the batch you are actually buying.
• Favor recent COAs. An old lab result on a different batch tells you little. The fresher the test, the more it means.
• Be skeptical of suspiciously cheap listings with no testing behind them.

That is exactly the comparison we put together. On our NAD+ product page you can compare vendor prices, see which batches have public lab data, and view the grades we assign from that data. From there you can head to the buy page to line up your options.

Questions, answered straight.