Combining NMN (nicotinamide mononucleotide), NR (nicotinamide riboside), and TMG (trimethylglycine) is a popular strategy in longevity routines. NMN and NR are direct, overlapping precursors used to boost cellular NAD⁺ levels for energy and repair, while TMG acts as a methyl donor to support safe methylation pathways and manage homocysteine.