A direct NAD+ precursor that efficiently raises cellular NAD+ levels — one of the most popular longevity supplements.
NMN (nicotinamide mononucleotide) is a nucleotide derived from ribose and nicotinamide that serves as a direct biosynthetic precursor to NAD+. It is converted to NAD+ inside cells by the enzyme NMNAT (nicotinamide mononucleotide adenylyltransferase). NMN supplementation aims to counteract the age-related decline in NAD+ levels.
NMN has gained massive popularity in the longevity community, largely driven by David Sinclair's research and public advocacy. Animal studies consistently show NMN supplementation improves multiple markers of aging: mitochondrial function, insulin sensitivity, exercise capacity, neurological function, and even fertility in aged mice.
The regulatory status of NMN became controversial in 2022-2023 when the FDA indicated that NMN could not be marketed as a dietary supplement because Metro International Biotech had previously filed an Investigational New Drug (IND) application for NMN, which technically excludes it from supplement classification. This decision remains contested.
Multiple human clinical trials have been completed. Studies show NMN supplementation (250-1200 mg/day orally) safely raises blood NAD+ levels. The TOME study showed improved muscle insulin sensitivity in overweight postmenopausal women. Exercise performance improvements have been reported in some studies.
Injectable NMN (subcutaneous) through compounding pharmacies provides higher bioavailability than oral supplementation. Human aging biomarker studies (epigenetic clocks, NAD+ metabolomics) are ongoing to determine whether NMN supplementation translates to meaningful biological age reduction.
📚 Key Reference: PMID: 33888596 (NMN human safety), PMID: 34238308 (TOME insulin sensitivity)
Oral NMN is well-tolerated at studied doses (up to 1200 mg/day). Mild GI effects possible. Injectable NMN: injection site reactions. Long-term safety data beyond 1 year is limited. Cancer concerns (NAD+ supports all cell growth, including potentially cancerous cells) remain theoretical. Consult your provider.
Regulatory status contested. FDA indicated NMN may not qualify as dietary supplement (2022-2023). Still widely sold as supplement. Injectable NMN available through compounding pharmacies. Under IND investigation by Metro International Biotech.