ah what a great question. i think i have a great answer! when you have medications in your house you can't guarantee that they are stored in the correct conditions (i bet many folks still keep everything in their bathroom cabinet). medications in the home get exposed to heat cold moisture light etc. unlike when they are stored in a pharmacy in their original container. this can lead to the breaking down of the medication which could cause the medication to not work as well or you can have an actual reaction to the components of the medication breaking down (so to answer your question it is not safe). if you notice on your prescription bottles it should have an expiration date from 1 year from the date you got the medication filled. this is to protect you from the possible scenarios i described above. it's always better to be safe than sorry.
i know most medications have an expiration date but what does that actually mean?