NAD+

Dinucleotide coenzyme (cellular cofactor)

Also known as: Nicotinamide adenine dinucleotide

Tier 2, Investigational, human data

Studied in registered human trials with published pharmacokinetic data, but not approved. Dosing outside a trial protocol has no established safety margin.

Half-life

Not established · intravenous

No plasma or elimination half-life for exogenous NAD+ is published in the peer-reviewed human literature. The only human pharmacokinetic data comes from a pilot study (Grant et al., 2019, PMC6751327) that infused NAD+ IV at 3 micromol/min (~2 mg/min) over 6 hours in male participants; it reported that no change in plasma NAD+ or its metabolites was seen until after ~2 hours and that NAD+ was rapidly and completely removed from plasma for at least the first 2 hours, but it did NOT calculate a plasma half-life. Because no source states a numeric half-life, valueHours and rangeHours are left null.

Dosing

500 - 750 mg

No standardized dose exists in the peer-reviewed literature. Values reflect doses actually used in small human studies on allowed sources: 500 mg (500000 mcg) per daily infusion for 4 consecutive days in a real-world tolerability study (PMC12907335), and ~750 mg (750000 mcg) total per 6-hour IV infusion session in the Grant et al. pharmacokinetic pilot (PMC6751327). These are research/commercial doses, not an established therapeutic range.

Regulatory status

NAD+ is not an FDA-approved drug. It is marketed as a dietary supplement (oral) and administered as a compounded intravenous or subcutaneous preparation in wellness/clinic settings; the tolerability study describes NAD+ IV as a commercial infusion product rather than an approved therapeutic (PMC12907335).

Evidence base

human clinical · confidence: low

Safety

Exogenous IV NAD+ is strongly infusion-rate dependent. In a retrospective tolerability study, all NAD+ recipients (n=6) reported moderate-to-severe abdominal cramping, diarrhea, nausea, vomiting, increased heart rate, throat pain, congestion and chest pressure during infusion; symptoms ceased immediately on completion, and participants self-slowed their infusions (mean ~97 min vs ~37 min for NR) to tolerate them (PMC12907335). By contrast, the slow 6-hour research infusion of ~750 mg reported no adverse events and only minor non-clinically-significant liver function changes (PMC6751327). Overall human safety data are limited to small pilot cohorts.

Sources