Which pain medicine does not thin your blood?

Acetaminophen. Acetaminophen [generic tyenol] does not thin your blood. If your iiver's healthy, don't take more than a total of 3000 mg a day. Watch out for Acetaminophen that may be combined with over-the-counter cold medications or prescription pain medicines [like vicodin or tyenol with codeine]. That counts in your grand total too.
Tylenol (acetaminophen) and narcotic. Nsaids (ibuprofen and aleve) and aspirin, both inhibit platelets, i.e. Thin the blood, and can contribute to minor bleeding when having surgery. Some people should never stop taking Aspirin if they have heart or vascular issues. Tylenol (acetaminophen) and all narcotics do not affect the blood at all, and are safe alternatives when taken as directed.