The reports on adverse drug reactions(ADR) to self-medication or over-the-counter medication are common across medical literature. However, the occurrence of oral fixed drug eruptions (FDE) to mefenamic acid is unique. We report a case of FDE to a drug obtained over the counter for menstrual pain. The essential findings from history, oral/ dental examination, diagnostic approach, and treatment are briefly discussed along with a note on time and dosing for the oral drug provocation tests. The occurrence of ADR may be avoided by spreading awareness against OTC medication and labeling the specific drug for patients with established ADR.