1-Methyladenine-13C,d3 s an isotopically labelled analog of 1-Methyladenine (M143935), which is a cytotoxic and mutagenic methylated nitrogenous base found in DNA resulting from endogenous and environmental alkylating agents. Its activity has been studied in relation to AlkB human homolog enzymes hABH2 and hABH3, which are oxidative DNA demethylases.