Yes. Every batch is independently assayed by an ISO/IEC 17025:2017-accredited laboratory (PJLA Accreditation No. 86258) in St. Petersburg, FL, with a Certificate of Analysis signed by Philias Daka, PhD, QA Manager. The most recent third-party report covers Lot 2430402, dated 02/21/2025, which verified 2,000 mg of Magnesium L-Threonate (Magtein) and 144 mg of elemental magnesium per 4-capsule serving by USP 38 Titration ā both PASS. Every batch is also screened for identity, heavy metals (arsenic, cadmium, lead, mercury via ICP-MS), and microbial contamination (Total Plate Count, Yeast & Mold, Coliform, E. coli, Salmonella, Staphylococcus aureus). Manufactured in a cGMP-certified U.S. facility from globally sourced ingredients.