NAD+

Nicotinamide adenine dinucleotide

Grade B: Human evidence, not approved for this use

TL;DR: Grade B: multiple human RCTs demonstrate that oral NAD+ precursors, primarily nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN), can raise blood NAD+ levels and, in some trials, improve metabolic markers in older adults. This is the strongest evidence base in this category. However, the critical distinction is that the RCT evidence applies to oral precursors, not to IV NAD+ infusions marketed by clinics. Direct IV NAD+ has only a small, non-randomized pilot study and retrospective tolerability data; its efficacy in raising intracellular NAD+ is uncertain because exogenously administered NAD+ cannot directly enter most cells and is substantially excreted in urine. Clinical benefits of IV administration, beyond precursor oral dosing, remain unproven.

Key Takeaways

Grade B: Human evidence, not approved for this use
Not FDA approved: Not FDA-approved as a drug in any form or route of administration. Oral NMN/NR are marketed as dietary supplements under a framework that does not require pre-market FDA approval or efficacy demonstration. IV NAD+ is compounded under state pharmacy and federal 503A/503B frameworks; the FDA has taken enforcement action against compounders not meeting sterile-preparation standards.
Compounding: Its federal compounding status is not separately established in the FDA bulk-substance lists we verify; confirm current status with a licensed pharmacist or physician before any use.

NAD+ chemical structure — Structure via PubChem CID 5892

Mechanism

NAD+ (nicotinamide adenine dinucleotide) is a coenzyme present in every cell, essential for energy metabolism (as an electron carrier in glycolysis and the citric acid cycle) and as a required substrate for sirtuins and PARP enzymes involved in DNA repair and gene regulation. NAD+ levels decline with age in many tissues. Oral precursors NMN and NR are transported into cells where they are converted to NAD+ through the salvage pathway, raising intracellular levels. Direct oral or IV NAD+ does not enter cells via a known transporter and is converted to precursors or excreted before reaching intracellular compartments.

Evidence

Grade B: multiple human RCTs demonstrate that oral NAD+ precursors, primarily nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN), can raise blood NAD+ levels and, in some trials, improve metabolic markers in older adults. This is the strongest evidence base in this category. However, the critical distinction is that the RCT evidence applies to oral precursors, not to IV NAD+ infusions marketed by clinics. Direct IV NAD+ has only a small, non-randomized pilot study and retrospective tolerability data; its efficacy in raising intracellular NAD+ is uncertain because exogenously administered NAD+ cannot directly enter most cells and is substantially excreted in urine. Clinical benefits of IV administration, beyond precursor oral dosing, remain unproven.

Safety and risks

Oral NMN and NR appear generally tolerable in short-term human trials, with mostly mild gastrointestinal side effects reported. IV NAD+ carries additional and more serious risks: the FDA has received adverse event reports following IV NAD+ use including severe chills, shaking, and vomiting requiring medical attention. Contamination risk is significant, the FDA has warned that food-grade NAD+ raw material (used by some compounders) is not suitable for sterile IV preparation and poses a risk of microbial and endotoxin contamination. Long-term safety data for either route is absent. High-dose NAD+ precursors may raise levels of the metabolite methyl-2-pyridone-5-carboxamide (2-PY), the implications of which are under investigation.

Interactions

Theoretical interaction with PARP inhibitors (e.g., olaparib) used in oncology, NAD+ is required for PARP activity, and raising NAD+ could theoretically antagonize PARP-inhibitor cancer therapy. No confirmed human pharmacokinetic interaction data exists. Consult an oncologist before use in any cancer context. High-dose niacin-pathway precursors may affect blood glucose regulation; caution in diabetes.

Compounding legality

Its federal compounding status is not separately established in the FDA bulk-substance lists we verify; confirm current status with a licensed pharmacist or physician before any use.

Sources

NAD+ is Not FDA approved. PeptideGrids presents evidence and regulatory status for informational purposes only. We do not sell, supply, source, or help anyone obtain this compound, and we provide no dosing or administration guidance. This is not medical advice; consult a licensed clinician. Full disclaimer.

Last reviewed June 1, 2026 by PeptideGrids editorial team (independently audited).