Two NAD+ precursors, two academic schools, two clinical-trial readouts. What the human data actually shows.
| NMN | NR | |
|---|---|---|
| Generic | Nicotinamide Mononucleotide | Nicotinamide Riboside |
| Backed by | David Sinclair (Harvard) | Charles Brenner (City of Hope), ChromaDex |
| Bioavailability | Debated (Slc12a8 transporter hypothesis) | Strong (NRK enzymes) |
| Typical dose | 500-1000 mg / day | 300-1000 mg / day |
| Cost / month | $30-50 | $60-100 |
| FDA status | Reclassified as drug 2022 (US) | GRAS supplement |
| NAD+ increase (RCT) | Modest, dose-dependent | Significant in blood NAD+ |
| Clinical outcomes | Minimal-to-modest | Minimal-to-modest |
NMN proponents claim direct cellular uptake via the Slc12a8 transporter. NR proponents argue NMN is dephosphorylated to NR in the gut anyway — and NR has well-established NRK-mediated cellular uptake. Most independent labs side with NR on bioavailability evidence, though the practical NAD+ increase is similar at equivalent doses.
In late 2022, FDA reclassified NMN as a drug subject to Investigational New Drug pathway, ending its supplement status in the US. Sales continued in a regulatory gray zone; quality varies dramatically by source. NR retains supplement (GRAS) status.
Both compounds raise blood NAD+ in human RCTs. Clinical outcomes — endurance, cognition, biomarkers of aging — show small effect sizes that often do not reach statistical significance. The honest read: cellular and biochemical effects are real, downstream clinical benefit is modest.
Pick NR if you want a clean supplement-regulated product with well-established bioavailability and a slightly higher cost. Pick NMN if you want the Sinclair-protocol option, can verify sourcing, and accept the higher regulatory uncertainty.
Epti lets you log your protocol — every dose, side-effect, and outcome on one timeline. The only way to know which works for you.