Source comparison
Best NAD+ Dosage for Neurodegeneration 2026: Clinical Comparison
NMN (oral) 500–900mg/day split-dose Direct Preiss-Handler entry High (crosses BBB via nucleoside transporters) Phase 2 data in Parkinson's, MCI Best-supported option for neurodegeneration. Superior CNS biomarker response NR (oral) 500–1000mg/day Requires NRK p
This comparison does not assign a generated winner or score.
- NMN (oral)
- 500–900mg/day split-dose
- Direct Preiss-Handler entry
- High (crosses BBB via nucleoside transporters)
- Phase 2 data in Parkinson's, MCI
- Best-supported option for neurodegeneration. Superior CNS biomarker response
- NR (oral)
- 500–1000mg/day
- Requires NRK phosphorylation first
- Moderate (two-step conversion reduces efficiency)
- Phase 2 data in Alzheimer's, aging
- Effective but metabolically less efficient than NMN for CNS targets
- NAD+ (IV infusion)
- 500–750mg per session
- Bypasses GI tract entirely
- Poor (minimal BBB transport)
- Observational only. No RCT CNS data
- Produces plasma elevation but inconsistent cerebrospinal NAD+ improvement
- Nicotinamide (oral)
- 500–1500mg/day
- Methylation-dependent salvage
- Moderate (methylation burden limits high-dose use)
- Phase 3 data in skin cancer prevention only
- Not recommended above 1000mg daily due to homocysteine elevation risk
- Niacin/Nicotinic Acid
- 1000–2000mg/day
- Converted to NAD+ via Preiss-Handler
- Low for CNS (flushing limits tolerability)
- No neurodegeneration RCT data
- Cardiovascular uses supported. Neurodegeneration evidence absent