N(Im)-Ethoxycarbonyl-S-ethoxycarbonyl L-Ergothioneine Methyl Ester Iodide-D3 is an isotope labeled analog of N(Im)-Ethoxycarbonyl-S-ethoxycarbonyl L-Ergothioneine Methyl Ester Iodide (E890475), which is an intermediate in the production of L-Ergothioneine.