An International Normalized Ratio of 2.0 to 3.0 is the acceptable range for most people taking warfarin according to Mayo Clinic. However, the desired INR target range may be slightly lower or higher for certain individuals.
An INR represents how long it takes for a person's blood to clot. Patients with a higher INR can be at risk of bleeding as it takes longer for their blood to clot, while patients with a lower INR can be at risk of developing blood clots. There are many factors that can affect how warfarin works, and the INR test helps in finding the appropriate warfarin dose for each person, according to NPS MedicineWise.