1. Should I do microneedling or stop Tretinoin for 3-5 days prior to microneedling? 2. Can I put tretinoin 0.1% on face then do microneedling 1mm? 3. After microneedling, what can I put on my face? Can I still use tretinoin and vitamin C later on that night? 4. Does PRP for the face contain platelet poor plasma and platelet rich plasma or only platelet rich plasma? What is your method? Thank you in advance!