Used in pharmaceutical research as a deuterated analog for metabolic stability studies, particularly in drug development involving kinase inhibitors. The deuterium substitution enhances resistance to oxidative metabolism, improving half-life and bioavailability in investigational compounds. Also employed as an internal standard in mass spectrometry for quantitative analysis of indole-based drugs. Its structural motif supports binding to purinergic receptors, making it useful in neuroscience and oncology research.