I take Elmiron 6 a day and just went in for surgery where they took a clotting time as I told them Elmiron can be a blood thinner in some people. The test results were fine and in the normal mid range. So for me on this dose the blood thining is not a factor. The package insert says that blood thining was possible on 2,000 mg a day give IV.
I have only had good results with Elmiron no side effects.