This is generally minimal as long at the PT/INR is kept in the therapeutic range. People on
warfarin, even at desireable levels, may notice that they bruise more easily than
usual. Otherwise, warfarin is well tolerated.
Side effects which sometimes occur include:
Hair loss
Nausea, vomiting, cramping or diarrhea (these are quite uncommon).
Low white blood cell counts.
These effects however are quite uncommon.