INR has gone below 2 and stayed there for a few weeks now. They keep upping the dose but it is having little impact. This means I have to inject Heparin (well family do as I can't stand needles) until it goes above 2. I have noticed my joints are really aching which they don't do when Warfarin is at the top of my range 3-3.5, does this mean that Heparin doesn't work for me? Also could I have developed a resistance to Warfarin having only been taking it for about a year and a half? A bit worried that all forms of anti-coagulation are stopping working for me - already had one stroke and don't want another because my body is fighting against stuff! I am seeing my Rheumatologist at the end of the month which might shed some light but wondered if anyone else had had a similar experience? By the way, I have not suddenly changed my diet and gone mad on broccoli or any other foods in vitamin K or started any new medication, so this not the cause. I did start taking a Milk Thistle supplement on the advice of my Hepatologist but this, if anything, would increase the INR - according to the research I have read. However to be on the safe side I have stopped taking it.