Acetaminophen-d7 is the deuterium labeled Acetaminophen. Acetaminophen (Paracetamol) is a selective cyclooxygenase-2 (COX-2) inhibitor with an IC50 of 25.8 µM, is a widely used antipyretic and analgesic agent. Acetaminophen is a potent hepatic N-acetyltransferase 2 (NAT2) inhibitor.