Dosing in the literature
The NAD+ doses the studies actually used, route by route
Oral precursor ranges, intravenous session protocols, and pharmacokinetics — reported strictly as study parameters, with no instruction for any individual.
Before the details
This page lists NAD+ dosage as it appears in the research — the amounts investigators gave, by which route, for how long. It is not a recommendation and contains no instruction to take anything. Because intact oral NAD+ is poorly absorbed, almost all oral dosing in the literature uses precursors (NMN, NR) rather than NAD+ itself [5]. Injectable and infusion protocols come from small studies and clinic practice, not validated trials. Read every figure below as a study parameter, then take dosing questions to a qualified clinician.
Doses Used in the Research Literature
Oral precursor doses cluster in narrow, repeatedly studied ranges. NMN has been studied at 250-900 mg/day orally in human RCTs, with 250 mg/day the most-replicated dose and up to 1200 mg/day investigated [5][1][3]. Nicotinamide riboside is commonly studied at 250-1000 mg/day, with up to 3000 mg/day tested for safety (the NR-SAFE design) in Parkinson's disease [5]. The older B3 vitamin nicotinamide has been studied at 500 mg twice daily for skin-cancer chemoprevention [5].
Parenteral protocols are far less standardized. Reported intravenous NAD+ wellness protocols span roughly 250-1000 mg per session over several hours, and a pharmacokinetic study used a continuous infusion at about 3 µmol/min over six hours [5]. The NADH Parkinson's studies used fixed research schedules — 25 mg daily for four days, or 10 mg over 30 minutes for 7 days [7][8]. These are the parameters of specific studies and protocols, presented here as research context only, never as a dose for any person. Each figure traces to the full reference list, where the species, route and source for every number can be checked.
How much NAD should I take?
This site reports only doses studied in research — NMN 250-900 mg/day, NR 250-1000 mg/day (up to 3000 mg/day tested for safety), IV protocols ~250-1000 mg/session [5][1][3] — as study parameters, not as a recommendation for any individual. The right amount, if any, is a question for a qualified clinician, not a digest.
Pharmacokinetics: clearance, absorption and what persists
The dosing picture only makes sense alongside the kinetics. NAD+ itself is not freely taken up intact by most cells, and infused intravenous NAD+ is cleared from plasma fast — a pilot study found near-complete plasma removal within the first ~2 hours of infusion [5]. Oral precursors behave differently: they are absorbed and raise whole-blood NAD+ over days to weeks, and that elevation is sustained through chronic dosing in 8-12 week trials rather than spiking and vanishing [4][3].
Stability shapes how injectable doses are handled. NAD+ and NMN are hygroscopic and degrade with heat and moisture, so reconstituted injectable NAD+ is kept cold and protected from light, and compounded injectables carry contamination risk — an FDA Class I recall has been issued for a compounded NAD+ injection over elevated endotoxin [5]. None of this constitutes a handling or dosing instruction; it is the documented pharmacokinetic and stability record.
Routes studied and how their evidence compares
Oral capsules and powders of NMN, NR and nicotinamide carry the bulk of controlled human evidence [5]. Intravenous NAD+ infusion is used in wellness settings with limited, mostly pilot or retrospective controlled data [5]. Subcutaneous and intramuscular NAD+ injection is compounded with minimal peer-reviewed pharmacokinetic data [5]. Sublingual, intranasal, topical and transdermal-patch routes are marketed but have little controlled evidence [5]. The pattern across routes is consistent: the more invasive the route, the thinner the controlled efficacy data — the opposite of what the marketing implies.