NAD+ Dosage in the Research Literature

Read this first

This page lists doses that appear in published NAD+ dosage research, and only that. It does not tell anyone what to take. NAD+ itself is barely absorbed when swallowed, so the oral studies use precursors (building blocks like NMN and NR). The numbers below are the amounts given to participants or animals in specific studies, with the species and route attached, so you can see what was actually tested. None of it is a recommendation, a protocol, or medical advice.

Doses Used in the Research Literature

Oral precursors carry the bulk of the controlled human evidence. NMN appears in human RCTs at 250-900 mg/day, with 250 mg/day the most-replicated dose and up to 1200 mg/day studied; the multicenter dose-response trial tested 300, 600, and 900 mg/day for 60 days and identified 600 mg/day as optimal ^[3]. The muscle-insulin-sensitivity trial used 250 mg/day for 10 weeks ^[1]. Nicotinamide riboside appears commonly at 250-1000 mg/day, with up to 3000 mg/day tested for safety (the NR-SAFE design in Parkinson's disease); the eight-week dose-response trial used 100, 300, and 1000 mg/day ^[4]. Nicotinamide (NAM) has been studied at 500 mg twice daily for skin-cancer chemoprevention ^[6].

For the infused route, reported IV NAD+ protocols run roughly 250-1000 mg per session over several hours, and one pharmacokinetic study used a 3 µmol/min continuous infusion over six hours ^[13]. These figures are documented amounts from the literature, attributed to their studies — not a schedule and not guidance.

Clearance and Half-Life: Infused NAD+ vs Oral Precursors

"Half-life" means two different things depending on the route. Infused NAD+ is rapidly cleared: a pilot pharmacokinetic study found near-complete removal of NAD+ from plasma within roughly the first two hours of infusion, with extensive extracellular metabolism along the way ^[13]. So the infused molecule does not linger as NAD+ in the blood.

Oral precursors behave on a different clock. Rather than tracking a plasma NAD+ half-life, the relevant readout is whole-blood NAD+, which rises over days to weeks and stays elevated through chronic dosing — NR's 22%/51%/142% rise was maintained across the full eight-week trial ^[4], and NMN's elevation held at days 30 and 60 ^[3]. After stopping, blood NAD+ returns toward baseline over the following weeks ^[13]. The takeaway: infused NAD+ is a transient plasma spike; oral precursors are a sustained shift in the blood NAD+ pool.

Routes studied

Four route families appear in the literature, with sharply different evidence weights. Oral capsules and powders of NMN, NR, and nicotinamide carry the bulk of controlled human data ^[3][4]. Intravenous NAD+ infusion is used in wellness settings but rests on limited, mostly pilot or retrospective data ^[13]. Subcutaneous and intramuscular NAD+ injection is compounded with minimal peer-reviewed pharmacokinetic data ^[6]. Sublingual, intranasal, topical, and transdermal patches are marketed but have little controlled evidence ^[6]. The bulk of human evidence is oral and for precursors; the further a route gets from that, the thinner the data.

Tolerability and Adverse Events Reported in Trials

Oral precursors were generally well tolerated in trials. NR showed no significant adverse-event difference from placebo at any dose through eight weeks, no flushing, and no LDL elevation ^[4]; NMN showed no safety issue at 300-900 mg/day over 60 days ^[3]. Reported NAD+ side effects cluster on the infused route: IV NAD+ run too fast can cause chest and abdominal discomfort, flushing, and nausea, which in a retrospective comparison resolved on completing the infusion ^[13]. The most serious documented risk is not pharmacological but a quality failure — the FDA Class I recall of a compounded NAD+ injection for elevated bacterial endotoxin ^[13]. Long-term oral NMN in mice suppressed age-associated weight gain rather than causing it ^[6]. These are reported study findings, not a safety assurance for any product or person.

Stability and storage notes

NAD+ and NMN are hygroscopic — they pull in moisture — and degrade with heat and humidity ^[6]. Reconstituted injectable NAD+ should be kept cold and protected from light ^[6]. Because compounded injectables have a documented endotoxin-contamination precedent (an FDA Class I recall), product quality and third-party testing are recurring concerns the literature flags ^[13]. Supplement-grade products also vary widely in purity and actual content, and third-party testing is not guaranteed ^[13]. This is context for reading the research, not buying guidance.

Regulatory and competitive status

NAD+ is not FDA-approved for any disease; it is marketed as a dietary supplement, and IV/injectable NAD+ is compounded rather than approved ^[13]. The supplement status of NMN specifically is contested — the FDA's position is that NMN was excluded from the supplement definition after being authorized for drug investigation, an unsettled marketplace dispute rather than a ban ^[13]. For readers asking about sport: NAD+ and its precursors (NMN, NR, nicotinamide) are not prohibited by WADA. None of this constitutes a clinical recommendation, and this site sells nothing.