I read a few times using stuff before fillers could cause a reaction, rash, etc to the skin as it is "irritated". I have 3 important questions: 1. Want to start using Retin A now, how long should I stop Retin A before getting fillers? AND 2. What could happen to you if you did have a reaction from using Retin A in conjunction with fillers? 3. How soon can you return using Retin A after you have received fillers?