Hi, I was wondering how long it takes Ativan to take take full effect. I need to take it for a specific situation (oral foreign language final ) and I wasn't sure if I should take it like 20 minutes before or a couple of hours or what? I don't want to take it too early and be tired. My prescription just said something like "take as needed" so I'm just not sure when to take it for the best result. Does anyone know?