Nicotinamide riboside (NR, sold as Niagen) and nicotinamide mononucleotide (NMN) are forms of vitamin B3 that the body converts into NAD+, a molecule cells use in energy metabolism. Oral NAD+ products usually contain one of these precursors.
Also known as: nicotinamide riboside, NR, Niagen, NMN, nicotinamide mononucleotide.
There is no intake value for NR or NMN. Human studies used NR at single doses of 100, 300 or 1,000 mg (Trammell 2016) and up to 1,000 mg twice daily (Airhart 2017), and NMN at single doses of 100, 250 or 500 mg (Irie 2020). These are study protocols, not a recommendation.
NR and NMN are sold as dietary supplements, and FDA does not approve dietary supplements before they are marketed. In 2016 FDA responded to a GRAS notice for nicotinamide riboside (GRN 635) that it had no questions about the company's conclusion that NR is generally recognized as safe for its intended food uses, while noting it had not made its own determination. NMN's supplement status has changed over time; we could not open FDA's own current documents on it, so we do not summarize them here. Injectable NAD+ is a separate product, covered on the NAD+ injection page.
In one study, 1,000 mg of NR raised blood NAD+ by about 100% and was well tolerated with no adverse events (Airhart 2017). In a single-dose NMN study, lab values stayed within normal ranges (Irie 2020).
The only measured half-life we found is for nicotinamide riboside in whole blood: about 2.7 hours, with blood levels peaking about 3 hours after a 1,000 mg dose, but only in half of the 8 people studied (Airhart 2017). No study we found reports a half-life or time to peak for NMN itself. Because the app's single entry covers both precursors, we do not list its 3-hour and 2-hour modeling values.