5-Hydroxy Tryptophol-d4 β-D-Glucuronide Methyl Ester is an intermediate used in the synthesis of 5-Hydroxy Tryptophol-d4 β-D-Glucuronide (H976012), which is a labeled metabolite of 5-Hydroxytryptamine (H974990), a tryptamine derivative; shows α-adrenolytic activities.