# Doses Used in NAD+ Research: Precursor Amounts, Routes, and Formats > NAD+ research-dose context: the NMN and NR amounts studied in human trials, the routes tested, and how oral, IV, and patch formats compare. No dosing advice; cited to source. What amounts the human trials administered, over what durations, by what routes — reported as studied figures, not as a recommendation. ## Before the details This page is a research digest, not medical advice, and it gives no instruction on what to take. What it does is report the amounts used in published NAD+ studies. The short summary: human trials of the precursors (NMN and NR — the building blocks the body turns into NAD+) used oral doses in the hundreds to low-thousands of milligrams per day over a couple of months, and they measured NAD+ in blood as it rose over days to weeks. The intact NAD+ molecule, by contrast, is poorly absorbed by mouth, and intravenous NAD+ is cleared from the blood fast. Routes and formats are compared below, each tied to its study. ## Doses Used in NAD+ Precursor Research Any discussion of NAD+ dosage in the literature is, in practice, a discussion of precursor doses, because the controlled human data sit almost entirely with the oral precursors. NMN has been studied at 250-900 mg/day in randomized trials, with 250 mg/day the most-replicated dose and up to 1200 mg/day examined; a multicenter trial flagged 600 mg/day as optimal among the doses it tested [3]. The 10-week insulin-sensitivity trial used 250 mg/day [1]. NR has been studied commonly at 250-1000 mg/day, with up to 3000 mg/day tested for safety in a Parkinson's-disease safety study; the dose-ranging trial used 100, 300, and 1000 mg/day [4]. Nicotinamide (NAM) has been studied at 500 mg twice daily in a skin-cancer chemoprevention context. These are amounts administered to study participants under supervision, with outcomes such as whole-blood NAD+, muscle insulin sensitivity, and walking distance as endpoints [1][3][4]. They are reported here as the studied figures; this digest makes no recommendation about any dose, route, or product. ## Routes studied: oral, intravenous, injection, and topical Four broad route classes appear in the literature, with very different evidence behind them. Oral capsules and powders of NMN, NR, and nicotinamide carry the bulk of the controlled human evidence [4]. Intravenous NAD+ infusion is used in wellness settings but rests on limited controlled data, mostly pilot and retrospective [12]; the [IV NAD research](/iv-nad) page covers it in full. Subcutaneous and intramuscular NAD+ injection is compounded and has minimal peer-reviewed pharmacokinetic data. Sublingual, intranasal, topical, and transdermal formats are marketed but thinly studied. The contrast in evidence weight across routes is itself one of the clearest findings: the more invasive the route, generally the thinner the controlled data. ## Liposomal, Sublingual and Patch Formats: Marketed but Thinly Studied Beyond standard oral capsules, NAD+ and its precursors are marketed in liposomal NAD+ preparations and in sublingual, intranasal, topical, and transdermal-patch formats — each promising better delivery of a molecule that is otherwise poorly absorbed. The controlled evidence behind these formats is thin. The human trial data that exist come overwhelmingly from oral precursor capsules and powders [4][3] and, more weakly, from IV infusion [12]; no cited trial in this digest establishes that a liposomal, sublingual, or patch NAD+ format raises whole-blood NAD+ or changes a clinical outcome. Described honestly, these are marketed delivery claims that the published literature has not yet tested at the level the oral precursors have been. ## How much NAD should I take? This is a research digest, not medical advice, and it gives no dosing instruction. For context only, human trials studied NMN at 250-1200 mg/day and NR at 250-3000 mg/day; a multicenter NMN trial identified 600 mg/day as optimal among the doses it tested [3]. Those are studied amounts, not a recommendation for anyone. ## What is the best time to take NAD, morning or night? The cited trials did not establish an optimal time of day. The NMN and NR randomized trials dosed daily over 8-10 weeks and measured blood NAD+ over days to weeks rather than within a single day [3][4]. No timing recommendation can be drawn from this literature. ## Do NAD patches work? Transdermal patches and other formats such as sublingual, intranasal, and topical NAD+ are marketed but have little controlled evidence behind them. The bulk of the human trial data comes from oral precursors (NMN, NR) [4][3] and, more weakly, from IV infusion [12]. No cited trial establishes that NAD+ patches raise NAD+ or change clinical outcomes. --- A flat, color-blocked index of the NAD+ literature — the coenzyme set apart from the precursors NMN and NR that rebuild it, what the trials measured stamped to each study and what they did not left in plain view; no clinic behind the index and nothing here infused, dispensed, or sold.