# NAD+ Dosage in Research: Doses, Routes and Tolerability | NAD+

> NAD+ dosage in research: NMN 250-900 mg/day, NR 250-1000 mg/day, IV ~250-1000 mg/session. Doses and tolerability reported from published studies — not dosing advice.

The precursor and infusion doses used in published studies, the routes, the half-life data, and the tolerability signals — reported for context, with no human dosing instructions.

## Before the details

This page reports the NAD+ dosage figures that appear in published research — what was given, to whom, by which route — purely for context. It is not a dosing guide and contains no recommendation to take anything. Most human data involve oral *precursors* (NMN, NR), because NAD+ itself is poorly absorbed [8]. Where doses appear below, they are study doses (often per kilogram in animals, or fixed daily amounts in human trials), and the species and route are always stated. Read these as descriptions of experiments, not instructions.

## Doses used in NAD+ precursor research

The doses studied cluster by molecule [3][4]. **NMN (precursor):** `250-900 mg/day` orally in human trials, with `250 mg/day` the most-replicated dose [1]; up to `1200 mg/day` has been studied. **Nicotinamide riboside (NR, precursor):** `250-1000 mg/day` orally is common [4], with up to `3000 mg/day` tested for safety (the NR-SAFE study) in Parkinson's disease. **IV NAD+ (wellness/clinical):** reported infusion protocols of about `250-1000 mg` per session over several hours; one pharmacokinetic study used a `3 µmol/min` continuous infusion over 6 hours. **Nicotinamide (NAM):** `500 mg` twice daily has been studied for skin-cancer chemoprevention. These figures are reported as study doses for research context, not as a personal recommendation.

## Half-life, absorption and what raises blood NAD+

The pharmacokinetics split sharply by route. NAD+ itself is not freely taken up intact by most cells; infused IV NAD+ is rapidly cleared — a pilot study found near-complete plasma removal within the first `~2 hours` of infusion [9]. Oral precursors behave very differently: they are absorbed and raise whole-blood NAD+ over days to weeks, with the elevation persisting through chronic dosing across `8-12 week` trials [3][4]. The NR dose-response — `+22%`/`+51%`/`+142%` at `100`/`300`/`1000 mg/day` — held throughout an 8-week study [4]. So "how long does it last" depends entirely on the route: IV NAD+ is gone from plasma in hours, while oral precursors maintain a raised blood NAD+ for as long as dosing continues.

## Routes studied

Four route families appear in the literature, with very uneven evidence [9]. **Oral** capsules and powders of NMN, NR and nicotinamide carry the bulk of controlled human data. **Intravenous** NAD+ infusion is used in wellness clinics but rests on limited, mostly pilot or retrospective data. **Subcutaneous and intramuscular** NAD+ injection is compounded with minimal peer-reviewed pharmacokinetic data. **Sublingual, intranasal, topical and transdermal patches** are marketed but have little controlled evidence behind them. The reliable human evidence is overwhelmingly oral-precursor; the further a route gets from that, the thinner the data.

## Do NAD patches work?

Transdermal patches, along with sublingual, intranasal and topical NAD+ products, are marketed but have little controlled evidence [9]. Nearly all of the reliable human data come from oral precursor capsules and powders, not patches. No cited trial here establishes that a NAD+ patch raises NAD+ or produces a clinical effect.

## Tolerability and safety signals in the NAD+ literature

Tolerability tracks closely with route and product quality. In randomized trials, oral NMN (`250-900 mg/day`) and NR (`100-1000 mg/day`, up to `3000 mg/day` in a Parkinson's safety study) were generally well tolerated over `8-12 weeks` with no significant adverse-event excess versus placebo [3][4]; NR specifically did not cause flushing or raise LDL cholesterol [4]. IV NAD+ is different: infusions run too fast can cause flushing, nausea and chest or abdominal discomfort, which typically eases when the infusion is slowed. A documented quality risk: a compounded injectable NAD+ product was subject to an FDA **Class I recall** 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. A separate, theoretical caution: because NAD+ supports proliferating cells, its role in cancer is context-dependent, so caution has been advised in cancer populations [13]. These are study observations and documented risks, not medical advice.

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An orbital reading of the NAD+ literature — the coenzyme at the core, its precursors NMN and NR held apart from the molecule itself, and the human, rodent and gap evidence each logged to source; no clinic behind the console and nothing here infused, dispensed or sold.