I take 1000 mg of nicotinamide mononucleotide (NMN) daily; what dose of nicotinamide riboside (NR) is safe to add?

Nicotinamide Riboside Dosing Recommendation with Concurrent NMN Use

Given your current 1000 mg daily NMN intake, you should not add nicotinamide riboside (NR) supplementation, as this combination significantly exceeds established safety thresholds for nicotinamide compounds and may increase cardiovascular risk.

Safety Threshold Analysis

The upper intake level (UL) for nicotinamide is 12.5 mg/kg body weight/day or approximately 900 mg/day for adults, as established by the European Food Safety Authority 1. Your current 1000 mg NMN dose already exceeds this threshold before considering any NR addition 2.

Key Safety Considerations:

• No adverse effects were observed at doses up to 25 mg/kg body weight/day in prolonged studies, but an uncertainty factor of 2 was applied to establish the 900 mg/day upper limit 1
• The 900 mg/day UL applies to total nicotinamide intake from all sources, not individual NAD+ precursors 2
• Both NMN and NR are converted to NAD+ through overlapping metabolic pathways, making their effects additive 2

Critical Cardiovascular Risk

High-dose NMN and NR supplementation (300 mg/kg and 230 mg/kg respectively in mice) promoted atherosclerosis despite improving dyslipidemia and fatty liver 3. While these were animal doses, the study specifically emphasized concerns about safe dosing for human clinical trials 3.

Dose-Dependent Effects:

• Doses around 100 mg/kg in mice had little harmful effects on atherosclerosis, suggesting a threshold effect 3
• Using standard allometric scaling for dose translation between species, human equivalent doses would be substantially lower than the animal doses tested 4
• Your current 1000 mg NMN dose (approximately 14 mg/kg for a 70 kg adult) is already in a range requiring caution 3

Monitoring Requirements if Continuing Current Dose

If you choose to continue your current 1000 mg NMN regimen without adding NR, implement these monitoring protocols:

• Hepatic transaminases (ALT, AST) at baseline and every 6 months, as liver enzyme elevations can occur at doses approaching or exceeding 1000 mg daily 2
• Discontinue immediately if transaminases exceed 2-3 times the upper limit of normal 2
• Baseline fasting glucose or hemoglobin A1c to monitor for metabolic effects 2
• Cardiovascular risk assessment given the atherosclerosis concerns from recent research 3

Alternative Approach

If you wish to add NR while maintaining NAD+ supplementation:

• Reduce NMN to 500 mg daily and add NR at 300-500 mg daily (standard FDA-approved dosing is 1-2 tablets once or twice daily) 5
• This keeps total nicotinamide precursor intake closer to the 900 mg/day safety threshold 1, 2
• Monitor as outlined above with particular attention to cardiovascular parameters 3

Common Pitfalls to Avoid

• Do not assume NMN and NR doses are independent—they both increase NAD+ through related pathways and their safety limits are cumulative 2
• Do not rely solely on subjective benefits—the atherosclerosis promotion occurred despite improvements in other metabolic parameters 3
• Do not ignore gastrointestinal symptoms (nausea, vomiting, diarrhea) as these may indicate excessive intake 6

Human clinical trials with NMN are ongoing but remain limited in long-term safety data, particularly at doses exceeding 900 mg daily 7. The most prudent approach is to reduce your current NMN dose rather than adding NR on top of it 1, 2, 3.