# NAD+ Doses Used in the Research (No Human Dosing Guidance) | NAD+ > NAD+ doses studied in the research: NMN 250–900 mg/day, NR 100–3000 mg/day, IV protocols. Reported strictly as what trials tested — no human dosing guidance. A cited digest. The doses NMN and NR trials actually tested, the routes studied, and how NAD+ clears — logged as research figures. No human dosing guidance is given here. ## Read this first This page reports the NAD+ doses that appear in published studies — nothing more. It is not a dosing guide, not a protocol and not a recommendation to take anything. When you see a number like "NMN 250 mg/day," read it as "this is the dose a particular trial administered to a particular group," not "this is what to take." NAD+ itself is barely absorbed when swallowed, so the doses that matter in human research are almost all *precursor* doses (NMN, NR — the building blocks). We log what was tested, the routes researchers used, and how the molecule clears. No human dosing instructions appear anywhere on this site. ## Doses Used in the Research (No Human Dosing Guidance) When people search "NAD+ dosage," the honest answer is a list of *studied* precursor doses, not a target to hit. Across human randomized trials, **NMN** was studied at 250–900 mg/day orally, with 250 mg/day the most-replicated dose [1][9][10] and a dose-ranging trial testing 300, 600 and 900 mg/day over 60 days and identifying 600 mg/day as optimal [3]; up to 1200 mg/day has been studied. **Nicotinamide riboside (NR)** was commonly studied at 250–1000 mg/day, with a clean dose-response of 100/300/1000 mg/day over 8 weeks [4] and `1000 mg twice daily` in heart failure [7]; it has been pushed to `3000 mg/day` in a Parkinson's-disease safety study. **IV NAD+** wellness protocols report roughly 250–1000 mg per session over several hours, and one pharmacokinetic study used a `3 µmol/min` continuous infusion over 6 hours. **Nicotinamide (NAM)** has been studied at `500 mg twice daily` for skin-cancer chemoprevention. Every figure here is a *studied* dose drawn from the literature — reported, not recommended. ## Why Oral NAD+ Differs From a Precursor (NAD+ vs NMN) The core of the NAD+ vs NMN question is bioavailability. NAD+ is a large, charged dinucleotide (`663.43 Da`), and it is not freely taken up intact by most cells — swallow plain "NAD+" and little reaches the inside of your cells as NAD+ [16]. Precursors solve this by being smaller, absorbable molecules the body assembles into NAD+ internally: NR and NMN enter the salvage machinery and lift the NAD+ pool from within [5]. That is why essentially every controlled human trial that successfully raised blood NAD+ used a *precursor*, not NAD+ itself [3][4][9]. So "NAD+ vs NMN" is not really a contest between two versions of the same supplement — it is the difference between a molecule that mostly cannot get in (oral NAD+) and a building block that can (NMN, NR). Some experts argue plain oral "NAD+" capsules are largely ineffective for this reason [16]. ## Routes studied Four route families appear in the literature, with very different evidence behind them. **Oral** capsules and powder of NMN, NR and nicotinamide carry the bulk of controlled human evidence [3][4][9]. **Intravenous** NAD+ infusion is used in wellness clinics but has limited controlled data — mostly pilot and retrospective [17]. **Subcutaneous / intramuscular** NAD+ injection is compounded with minimal peer-reviewed pharmacokinetic data — the [injectable and IV NAD+ risks](/nad-safety) are covered on the safety page. **Sublingual, intranasal, topical and transdermal patches** are marketed with little controlled evidence — except topical *nicotinamide*, which has clinical-trial support specifically for skin aging and pigmentation [13]. The weight of route evidence sits firmly on oral precursors; the further you get from that, the thinner the data. ## Clearance and Persistence in the Research There is no single NAD+ half life — how long NAD+ sticks around depends entirely on the route. Infused IV NAD+ is rapidly cleared from plasma — a pilot study found near-complete plasma removal within roughly the first two hours of infusion [17] — which is part of why IV's controlled evidence is weak. Oral precursors behave differently: they are absorbed and raise *whole-blood* NAD+ over days to weeks, and the elevation persists through chronic dosing in 8–12-week trials [4][9]. The effect is also reversible: after stopping NMN at 250 mg/day, blood NAD+ returned to baseline by about week 16 [9]. Single-dose pharmacokinetic work on oral NR showed dose-proportional rises in NR and NAD+ metabolites, with the metabolite NAAD reported with a half-life around 8 hours and used as a robust biomarker of pathway flux [8]. NMN and NAD+ are also hygroscopic and degrade with heat and moisture, and reconstituted injectable NAD+ should be kept cold and protected from light [16]. ## How much NAD should I take? Studies used NMN 250–900 mg/day [1][3][9] and NR 100–3000 mg/day [4][7]. These are doses tested in research, not a dosing recommendation — no human dosing guidance is given here. Which dose, if any, is appropriate for a given person is a question for that person and a qualified clinician, not for this digest. --- The NAD+ hype screenshotted and stapled to its source — the precursor trials that genuinely raised blood NAD+ stamped confirmed, the hard-outcome claims stamped preliminary, oral precursors kept apart from the compounded IV NAD+ behind a Class I recall, and the contested NMN status read as a dispute, not a ban; no clinic behind this corkboard and nothing here dosed, infused, prescribed, or sold.