NMN (Nicotinamide mononucleotide)

NMN is a nucleotide and NAD+ precursor in the salvage pathway, feeding into a coenzyme central to energy metabolism, sirtuin activity, and DNA repair. Oral NMN is absorbed and raises blood NAD+ in humans, but evidence for clinical longevity benefits remains limited. Trials report modest improvements on specific endpoints such as the 6-minute walk test, muscle insulin sensitivity, or grip strength; large, long-term outcome studies are lacking. NMN's US dietary supplement status was contested from 2022 to 2025, when the FDA reversed its earlier drug-exclusion ruling and confirmed that NMN may lawfully be marketed as a dietary supplement. On 13 May 2026 the European Food Safety Authority (EFSA) issued a positive scientific opinion on EffePharm's β-NMN (Uthever®) with a proposed safe upper intake of 300 mg/day for healthy adults (excluding pregnant and lactating women); European Commission authorisation as a Novel Food remains pending. Regulatory status in other regions varies.