As tranexamic acid (TXA) becomes more prevalent, all patients are receiving the same dose regardless of their pre-operative risk of transfusion. Therefore the aim of the study is to determine whether or not repeated dosing of oral TXA reduces the post-operative reduction in hemoglobin, hematocrit, number of transfusions, and post-operative blood loss following primary TKA and THA surgeries in patients with low pre-operative hematocrit and high risk for transfusion. The investigators hypothesize that a multi-dose TXA regimen will significantly minimize post-operative blood loss and transfusion requirements compared to the use of a single dose regime.