Taking plan b back to back?

Does taking plan b back to back bad? I’m asking for a friend. I have not personally ever took plan b then have to take it again the next day. My friend is freaking out. He doesn’t know what to do. He hooking up with his coworker and they were not using protection last night and then he comes to me again asking for help because it happened again. So my question is if she takes another plan b tomorrow is it still going to work?