Over the counter cough syrup is a weird category. It is an old drug, and some of the studies are mixed. The FDA regulations weren't the same back then, and so i

Over the counter cough syrup is a weird category. It is an old drug, and some of the studies are mixed. The FDA regulations weren't the same back then, and so it still has the approval. It has some issues when kids take a whole bottle, which means some places restrict its sale - but overall, it hasn't proved harmful to folks either. Cough drops are another one. There isn't much evidence they make you breathe better, yet people report that they do. They think this is likely due to the reaction menthol has on mucus membranes - it feels cool on the air one is breathing so they feel their breath. Yet, menthol is considered a drug and as such, it must have an FDA approval. Edit: I know these aren't prescription, but they were the first ones I thought of.