This single-center, prospective, randomized, double-blind controlled trial evaluated whether intravenous (IV) or intra-articular (IA) administration of tranexamic acid (TXA) improves intraoperative visual clarity, compared with a no-TXA control, during arthroscopic rotator cuff repair. Patients with full-thickness rotator cuff tears were randomly allocated to one of three groups: a control group receiving no TXA; an IA group in which 500 mg of TXA was added to each 1 L of normal-saline irrigation fluid; and an IV group receiving 1000 mg of TXA intravenously 10 minutes before surgery. The operating surgeon graded visual clarity on a 0-10 numeric scale at the end of each of six predefined surgical stages. Secondary outcomes included total operative time, estimated blood loss, irrigation-fluid volume, the number of irrigation-pressure increases, postoperative shoulder swelling, and postoperative day 1 pain.