over-the-counter drug; OTC medicine
Refers to medicines that can be purchased without a prescription at pharmacies or drugstores.
When I have a cold, I see how it goes with over-the-counter medicine.
This OTC drug does not contain ingredients that cause drowsiness.
一般用医薬品 is a formal term for OTC drugs, often used in official contexts, whereas 市販薬 is more common in everyday speech.
Compound of 市販 (market sale, commercially available) and 薬 (medicine).