# NAD+ Dosage in the Research: Oral Precursors, Injection, and IV Routes | NAD+

> NAD+ dosage as studied in research: oral NMN and NR ranges, IV/injectable NAD+ as an unapproved compounded route, and pharmacokinetics. No dosing instructions.

What the trials administered — oral precursor ranges, the compounded injectable route, and how the body handles each — reported as research context, never as instructions.

## The short version

This page reports **NAD+ dosage** the way the studies report it — which doses were given, to whom, by which route — and nothing more. It is not a how-to. Most controlled evidence is oral, using precursors (the building blocks the body turns into NAD+): NMN around 250-900 mg/day and NR around 250-1000 mg/day in trials. Injectable and IV NAD+ are a different, unapproved story: compounded, lightly studied, and carrying real quality risks. Where you see a number here, it points to a cited study of a defined population. This digest gives no personal dosing advice and recommends no product.

## Doses studied in the research literature

In controlled human trials, oral NAD+ precursors clustered in well-defined ranges. NMN was studied at 250-900 mg/day: 250 mg/day for 10 weeks improved muscle insulin sensitivity in prediabetic women [1], and 300, 600, and 900 mg/day for 60 days raised blood NAD+ dose-dependently, with 600 mg/day flagged as optimal [3]. Nicotinamide riboside (NR) was studied at 100-1000 mg/day, producing the 22%/51%/142% whole-blood NAD+ dose-response over eight weeks [4], and was tested up to 3000 mg/day for safety in a Parkinson's-disease study. Nicotinamide (NAM) has been studied at 500 mg twice daily for skin-cancer chemoprevention. These are [doses studied in the literature](/dosage) in defined trial populations, reported as research context — not a recommendation to take any amount.

## Injectable and IV NAD+: an unapproved compounded route

Injectable and IV NAD+ sit entirely outside the controlled-trial base that supports oral precursors. NAD+ delivered by injection or infusion is a *compounded* preparation — not FDA-approved — used in wellness and some clinical settings, with only pilot and retrospective data behind it. Reported infusion protocols run roughly 250-1000 mg per session over several hours; one pharmacokinetic study used a continuous 3 micromol/min infusion over six hours. The quality risk is documented, not hypothetical: a compounded injectable NAD+ product was subject to an FDA Class I recall — the agency's most serious category — for elevated bacterial endotoxin. NAD+ and NMN are also hygroscopic and degrade with heat and moisture, and reconstituted injectable NAD+ should be kept cold and protected from light. This is presented as an unapproved compounded route with documented quality concerns, never as an approved treatment.

## What controlled data exist on IV NAD+ therapy

IV NAD+ therapy has the weakest controlled evidence in the entire field. The defining pharmacokinetic observation: in a pilot infusion study, plasma NAD+ barely rose for roughly the first two hours of infusion, indicating extensive extracellular metabolism and that infused NAD+ is rapidly cleared from plasma. Most published IV work is pilot or retrospective rather than randomized, and infusion-related symptoms (GI discomfort, chest pressure, flushing) are reported when infusions run fast. No validated clinical benefit or dosing-timing protocol has been established for IV NAD+. The literature does not support broad efficacy claims for this route — a point this digest keeps deliberately unambiguous.

## Pharmacokinetics: how the body handles NAD+ and its precursors

The pharmacokinetics explain why route matters so much. NAD+ itself is not freely taken up intact by most cells, which is the practical case for using precursors orally [5]. Infused IV NAD+ is rapidly cleared from plasma — near-complete removal within the first ~2 hours of one pilot infusion. Oral precursors behave differently: NMN and NR are absorbed and raise whole-blood NAD+ over days to weeks, with the elevation sustained through chronic dosing across 8-12 week trials [4][3]. NAD+ synthesis also follows a circadian rhythm because NAMPT, the rate-limiting salvage enzyme, is clock-regulated [14] — biologically interesting, but not translated into any validated dosing-time recommendation. Routes studied span oral (the bulk of the evidence), IV infusion, subcutaneous/intramuscular injection (minimal peer-reviewed PK), and marketed sublingual, intranasal, and transdermal-patch formats with little controlled evidence.

---

An arcade-console reading of the NAD+ literature — the coenzyme logged apart from its precursors NMN and NR, the blood-NAD+ the trials actually moved scored against the gaps the rodent and IV data leave open; no clinic behind the console, nothing here infused, ordered, or sold.