For a person not on anticoagulant therapy, normal INR values typically range from 0.8 to 1.2. However, for patients taking anticoagulants like warfarin, the target INR range is usually between 2.0 and 3.0, though it can vary depending on the condition being treated. It's important to maintain INR within the therapeutic range to avoid risks associated with over-anticoagulation or under-anticoagulation.