Amounts in context
Study amounts for NAD+, NR and NMN
An amount is useful only with its chemical, route and study population attached. These entries describe experiments and provide no personal dosing instructions.
Oral NR amounts
The Conze trial gave healthy overweight adults 100, 300, or 1000 mg/day of NR for 8 weeks. Blood NAD+ rose 22%, 51%, and 142%, respectively; adverse events did not differ significantly from placebo.
For the brain question, NADPARK used 1000 mg/day for 30 days in people with Parkinson’s disease. The mild cognitive impairment trial used 1 g/day for 10 weeks in older adults. I prefer these complete entries to a freestanding range: the same chemical was being asked to answer different questions.
Oral NMN amounts
The muscle study gave prediabetic, postmenopausal women 250 mg/day for 10 weeks. Muscle insulin sensitivity improved while body composition and HbA1c stayed unchanged.
In the middle-aged adult trial, the groups received 300, 600, or 900 mg/day for 60 days. Blood NAD+ and walking distance increased. The authors’ preference for 600 mg/day describes their trial comparison. It cannot choose an amount for somebody outside that experiment.
NR-SAFE and tolerability
The NR-SAFE study in Parkinson’s disease tested 3000 mg/day for 30 days. No moderate or severe adverse events were reported, and the NAD+ metabolome increased without methyl-donor depletion. Clinical Parkinson’s severity did not significantly improve over that interval.
I read the duration as carefully as the amount here. A short safety study can describe the events observed in its participants; uncommon or delayed harm needs a much larger and longer record.
NAD+ precursor and route
A precursor is material used to make another molecule. NR and NMN feed NAD+ synthesis, whereas an IV contains NAD+ itself. The chemical conversion and route prevent a milligram-for-milligram comparison from answering how the body handles them.
The IV literature review describes historical addiction regimens and calls for rigorous randomized trials. For my purposes, those regimens are historical exhibits. They establish neither an optimal general-use amount nor a treatment schedule.
NAD+ half life
The phrase invites a single neat figure. The papers here concern several different measurements: continued blood elevation during oral precursor trials and the processing of extracellular NAD. In the fibroblast experiment, human skin cells grown in a dish took up breakdown products after NAD was processed outside the cells.
That finding supplies no human injection half life. Nor do the sustained blood readings during the 8-week NR trial tell us how long one dose acts after treatment stops. The IV record examines this chemical handling in more detail.
NAD+ side effects
Short oral trials reported tolerability within their studied populations. The IV review describes chest or abdominal discomfort, flushing and nausea associated with infusion rate. Compounded injectable NAD+ also carries contamination risk: elevated bacterial endotoxin prompted a Class I FDA recall of a compounded NAD+ injection.
Cancer adds a context-dependent concern because NAD+ supports cell metabolism, including that of existing tumors. The cellular metabolism review provides the biological background; a personal cancer history calls for clinical assessment. The evidence does not quantify that risk for an individual.