Antifibrinolytic therapy has been used for almost forty years for menorrhagia - the first publication was in 1965. It has previously been described that fibrinolysis is increased in the menstrual fluid and endometrium in women with heavy menstrual flow. Tranexamic acid, which is a fibrinolytic inhibitor, competitively blocks the activation of plasminogen to plasmin and thereby reducing fibrinolysis. Tranexamic acid reduces menstrual blood loss by up to 50% and it has been shown to be at least as equally as effective as oral contraceptives, NSAIDs, and intranasal desmopressin. There is no consensus as to the minimal effective dose, the dose scheduling and the optimal duration of therapy. In the published literature, the effective dose is variable and ranges from 1000 mg/day to 6000 mg/day. The recommended dose by the Compendium of Pharmaceuticals and Specialties (CPS), 2009, published by the Canadian Pharmacists Association, is 3000 mg/day to 6000 mg/day. The current recommended dose as per the Clinical Practice Guidelines for the Management of Abnormal Uterine Bleeding by the Society of Obstetricians and Gynecologists of Canada and the Canadian Hemophilia Society document on the Management of Women with Bleeding Disorders is 1000 mg orally four times a day. Interestingly, in China, it is recommended to give 2000 mg/day. The recommended duration of therapy is also variable; the CPS states the medication should be started "when the flow is copious" and taken for "several days." Most clinical trials have used a 4-5 day duration of therapy. It is given in different schedules, most commonly 3 to 4 times per day. A recent study compared two doses of tranexamic acid, 2000 mg/day vs. 1000 mg/day, both doses given on a twice-a-day schedule, with an additional placebo arm, assessing the effect on prevention of menorrhagia in women with intrauterine devices (IUDs). The women randomized to the tranexamic acid arms had significantly less menstrual flow compared with the placebo group and there was no significant difference in efficacy between the two doses of tranexamic acid. Women with underlying bleeding disorders may need higher doses than women without bleeding disorders; however, this is uncertain. This medication is not without toxicity and up to one-third of women experience side effects that are dose dependant. The most common adverse effects are nausea, vomiting, diarrhea and, less common, are headaches, dizziness and allergic reaction. Tranexamic acid is expensive; the retail price is $1.34/500-mg capsule. For example a dose of 4000 mg/day for 5 days would cost a patient $64.34/month including the dispensing fee. Common reasons for discontinuing the medication include side effects, cost and the inconvenience associated with multiple dosing. Many patients will adjust their dose - finding a balance of efficacy, minimal toxicity, cost, and frequency of dosing. It is our experience that some patients find this balance with a minimal dose of 500 mg taken twice daily. In this study we propose to investigate whether the minimal effective and tolerated dose of tranexamic acid, based on the PBAC score, quality of life factors, and tolerability of side effects is less than the current Canadian recommended dose of 1000 mg orally four times a day.