Compositions for addressing one or more of the effects of aging are described. The compositions comprise a first component comprising repair system activator(s) such as nicotinamide adenine dinucleotide (NAD+), nicotinamide mononucleotide (NMN), nicotinamide riboside (NR), nicotinic acid adenine mononucleotide (NaMN), nicotinic acid adenine dinucleotide (NaAD), nicotinic acid riboside (NAR), 1-methylnicotinamide (MNM), cyclic adenosine monophosphate (cAMP) and combinations thereof； a second component comprising methyl donor(s) such as S-5'-adenosyl-L-methionine (SAM), methionine, betaine, choline, folate, vitamin B12, or combinations thereof； and a third component comprising antioxidant defense activators such as H
