Yes. Every batch is third-party tested by an ISO/IEC 17025-accredited laboratory for identity, L-theanine purity, heavy metals, and microbial safety. L-theanine is verified by HPLC against the L-theanine reference standard, confirming the pure L-isomer (the bioactive form used in published clinical research, distinct from the D-isomer or D/L racemic mixtures). The full COA panel also covers four heavy metals via ICP-MS (arsenic, cadmium, lead, mercury against USP <2232> limits) and six microbial screens (Total Plate Count, Yeast & Mold, Coliform, E. coli, Salmonella, Staphylococcus aureus per USP and AOAC methods). Manufactured in a cGMP-certified U.S. facility.