# NAD+ Dosage: Doses Studied in the Research Literature, Filed by Route > NAD+ dosage as a research record: the NMN (250–900 mg/day) and NR (250–1000 mg/day) doses studied in human trials, the routes, and tolerability — listed as study parameters, not instructions. Cited. What precursors were given, at what doses, by what route, for how long — read as trial parameters from the published record, never as a dosing instruction. ## Start here This page catalogues the NAD+ dosage figures that appear in published studies — the amounts of precursor (NMN and NR, the building blocks the body turns into NAD+) that researchers actually gave participants. These are study parameters: the doses a trial used, reported so a reader can interpret the results below. They are not a recommendation, and this digest gives no instructions for human use. Plain NAD+ swallowed as a pill is poorly absorbed, so nearly all of these doses are precursors, and the injectable route is filed separately under its caveats. ## Doses studied in the research literature Across the human trials, the NAD+ dosage figures cluster by precursor. Oral NMN was studied at 250–900 mg/day, with 250 mg/day the most-replicated dose [1][6][7] and 300–900 mg/day used in the multicenter dose-ranging trial that named 600 mg/day optimal [3]. Oral NR was studied at 100–1000 mg/day in its core dose-response trial [4], with the broader literature running 250–1000 mg/day commonly and up to 2,000 mg/day for 20 weeks tested for safety with no serious adverse events [8]. Nicotinamide (NAM), the older vitamin-B3 form, has been studied at 500 mg twice daily in a separate skin-cancer chemoprevention context. For the compounded routes, reported IV NAD+ protocols run roughly 250–1000 mg per session over several hours, and a pharmacokinetic study used a continuous infusion across six hours — figures recorded here strictly as what protocols have used, not as endorsed practice. Again: these are study parameters. No dose on this page is offered as guidance for human use. ## Routes studied, and why the route changes everything The route is not a detail — it is the variable that most determines whether NAD+ rises and for how long. Oral capsules and powders of NMN, NR, and nicotinamide carry the bulk of the controlled human evidence and reliably raise blood NAD+ over days to weeks [4][6]. Intravenous NAD+ infusion, used in wellness clinics, has limited controlled data — mostly pilot or retrospective — and the infused coenzyme is rapidly cleared from plasma. Subcutaneous and intramuscular NAD+ injections are compounded with minimal peer-reviewed pharmacokinetic data, and sublingual, intranasal, topical, and transdermal patches are marketed with little controlled evidence. The further a route gets from oral precursors, the thinner the data. Stability shapes handling too: NAD+ and NMN are hygroscopic and degrade with heat and moisture, and reconstituted injectable NAD+ must be kept cold and protected from light. Compounded injectables carry a contamination risk — an FDA Class I recall has been issued for a compounded NAD+ injection over elevated endotoxin [8]. ## Tolerability and reported adverse effects in trials On NAD+ side effects, the oral precursor trials read reassuringly within their own scope. NR produced no flushing at 100–1000 mg/day and showed no significant adverse-event difference from placebo, without elevating LDL cholesterol [4]. NMN trials at 250–900 mg/day reported no safety issues and no serious adverse events across 60 days to 24 weeks [3][6][8]. The 2023 review confirmed safety across compounds and doses, with NR tested to 2,000 mg/day for 20 weeks [8]. The injectable route is where the discomfort sits: IV NAD+ run too fast can cause flushing, nausea, and chest or abdominal pressure, transient effects tied to infusion rate [14]. The documented hard risk is contamination, not pharmacology — the FDA Class I endotoxin recall of a compounded NAD+ injection [8]. A theoretical concern also runs through the cancer literature: because NAD+ supports proliferating cells, its role in oncology is dual and context-dependent, so caution is advised in cancer populations [14][12]. ## How much NAD should I take? This digest gives no human dosing instruction. The research doses studied include NMN 250–900 mg/day and NR 250–1000 mg/day, with NR tested up to 2,000 mg/day for safety [4][8]. Those figures are reported as study parameters — what trials administered — not as guidance. The decision to use any supplement belongs with a qualified clinician, not a reading of the literature. --- A night-edition broadsheet on the NAD+ record — the coenzyme filed apart from the NMN and NR precursors that rebuild it, the human trials that raised blood NAD+ kept on their own desk from the poorly-absorbed oral pill and the rapidly-cleared IV drip, and the contested NMN status posted as filed; no clinic behind this masthead and nothing here prescribed, compounded, or sold.