Simplify the following text for a Grade 9 native English-speaking person.
Original: Over time , often 3 â `` 5 years , drugs that prove themselves safe and appropriate as prescription medicines may be switched from prescription to OTC . An example of this is diphenhydramine ( Benadryl ) , which once required a prescription but now is available OTC nearly everywhere .
Simplified: Many OTC drug ingredients which were prescription drugs are now considered safe enough for use without a prescription .