NAD dosage: which numbers came from trials and which came from clinics

Two kinds of number, presented as one

The dosage figures in circulation come from two entirely different places. Oral precursor doses come from randomized trials that measured blood NAD and, occasionally, a functional endpoint. Injectable doses come from standard operating procedures written by clinics and compounding pharmacies.

Both appear in the same search results, formatted identically as charts. Only one kind has a study behind it, and the difference is invisible unless someone tells you.

The oral NAD dosage numbers that came from trials

Early / mixed evidence A dose-ranging randomized, multicenter, double-blind trial in healthy middle-aged adults found blood NAD rising with dose and reported oral dosing safe and well tolerated up to 900 mg daily.^[1] A separate trial gave 250 mg daily for twelve weeks, split as 125 mg twice daily, with the same result.^[2]

Those are genuine dose data. What they establish is that the compound is tolerable at those amounts and that it raises the marker it is supposed to raise. Neither trial identified a dose that produced a benefit, because that was not what either was designed to find.

That is a very high dose, and it is a dose that is higher than has ever been clinically tested.

The injectable numbers that came from protocols

Live search results for this term are dominated by compounding pharmacies and infusion clinics publishing dosing charts. The figures cluster consistently: subcutaneous protocols starting around 20 mg and titrating toward 100 mg, injections one to three times weekly, with intravenous sessions running to several hundred milligrams over several hours.

Read those as what they are. A standard operating procedure describes how a provider administers a product. It is not a dose-finding study, it has no control group, and the outcome it was optimized against is tolerability rather than benefit. The consistency between clinics reflects a shared commercial template more than a shared evidence base.

Why the infusions take so long

Because speed causes the symptoms. Flushing, chest pressure, nausea and cramping during a drip are widely described, and the standard remedy is to slow the rate. A session stretched over several hours is a tolerability management strategy, and it explains the price as much as the pharmacology does.

Our page on the side effect profile by route goes through that difference in full, including the regulatory position on compounded injectables.

What no NAD dosage has established

The gap under all of this is the same one that runs through the whole category. Supplementation with a precursor successfully raised NAD in human skeletal muscle and produced no improvement in muscle function or mitochondrial measures.^[3]

If raising the marker does not reliably move the outcome, then the dose that raises the marker most is not obviously the dose worth taking. Optimizing a number whose relationship to benefit is unproven is an expensive way to be precise about nothing.

Nicotinamide riboside had no effects on metabolic function, motor function, or exercise capacity and performance.

Where the real dose ceiling comes from

For nicotinamide, which is frequently included in NAD products, adverse effects including headache, dizziness and vomiting have been documented in healthy people at multi-gram doses, alongside mechanistic questions about the methyl donors its metabolism consumes.^[4] Reviews of NAD-boosting strategies raise related concerns about high-dose niacin, blood sugar and homocysteine.^[5]

So the practical ceiling is not set by NMN or NR, whose reported tolerability is good, but by the older B3 compounds sitting alongside them in many formulations. Checking the label matters more than choosing between 250 mg and 500 mg of the headline ingredient.

How to read any NAD dosage chart

Ask three questions. Who published it, and do they sell the thing it describes? Which route is it for, since oral and injectable are not comparable? And what was the number optimized against, an outcome or the absence of complaints?

Institutional summaries remain more measured than the commercial ones, describing the supplements as generally well tolerated while noting how limited the evidence is.^[6] Coverage of the wider NAD boom has made the same point about how far the market has run ahead of the data.^[7] Our pages on what NAD does, the NMN dose evidence and the booster category cover the rest.

Frequently asked questions

What is the correct NAD dosage?

There is no approved dosage for any route. Oral precursors have been studied at 250 mg to 1,200 mg daily. Injectable protocols in circulation typically run 20 mg to 100 mg subcutaneously one to three times weekly, and those figures come from clinic and compounding pharmacy protocols rather than from trials.

How much NAD should I take per day?

For oral precursors, the studied range starts at 250 mg daily, which is the dose used in a twelve-week safety trial and in the strongest efficacy trial in this family. Higher amounts raise the blood marker further without any demonstrated benefit attached to doing so.

What is the starting dose for NAD injections?

Published clinic protocols commonly start around 20 mg subcutaneously and titrate upward toward 100 mg. Those are operating procedures written by the clinics and pharmacies providing the service, not doses established by any randomized study.

Is there an FDA-approved NAD dose?

No. There is no approved dosage or regimen for NAD by any route, and injectable NAD is a compounded preparation rather than an approved finished drug product. Every chart you find is a protocol, not a label.

How often should NAD injections be given?

Circulating protocols range from one to three times weekly, with loading schedules and maintenance schedules that differ by provider. The variation between providers is itself informative: there is no standard because nothing has been standardized against an outcome.

Why do IV NAD infusions take hours?

Because infusing quickly produces flushing, chest tightness, nausea and cramping. Slowing the drip resolves them. The multi-hour session length is a tolerability management decision rather than a pharmacological requirement.

Is oral or injectable NAD dosing better?

Neither has demonstrated a functional benefit, so the comparison has no outcome to settle it on. Oral precursors have actual randomized trials behind their doses. Injectables have clinic protocols and a much higher price.

Does NAD dosage depend on body weight?

No human dosing study has established weight-based dosing for any route. Trials used fixed oral doses. Weight-based charts appear online and are extrapolated rather than measured.

What is the maximum safe NAD dose?

No upper limit has been established for any route. Oral trials found tolerability up to 900 mg daily over weeks. For nicotinamide specifically, adverse effects including headache, dizziness and vomiting have been documented at multi-gram doses.

Should the dose be split through the day?

One safety trial used 125 mg twice daily rather than a single 250 mg dose, and no study has compared the two schedules. Splitting is a reasonable habit rather than an evidence-based instruction.

How long before an NAD dose does anything?

Blood NAD precursor levels rise within one to two weeks of oral dosing. Functional changes, in the small number of trials reporting any, took eight to twelve weeks. Anything felt during an infusion is not the coenzyme working.

Do higher doses raise NAD more?

Yes, dose-dependently, which the dose-ranging trial demonstrated clearly. The unresolved problem is that a trial raising NAD in human muscle found no improvement in muscle function, so raising the marker further is not obviously worth paying for.

What monitoring goes with NAD dosing?

Nothing is formally required, since none of this is an approved therapy. If you are on medication for diabetes, glucose is worth watching given the effects reported across this compound family in both directions.

So what should someone actually do?

If taking an oral precursor, staying inside the studied range and starting at the low end is the defensible position. If considering an infusion, the questions worth asking are what is being infused, compounded by whom, at what rate, and on what evidence the protocol was written.