I was prescribed Doxycycline and Retin-A for my acne and said that it wouldn't affect my beard transplant, but just to be sure..

Thank you for your question. I do not think Doxycycline or Retin-A will affect the hair transplant procedure. Please talk to your Hair Transplant Surgeon in addition to your Dermatologist. All The Best !

The reason why you are taking the medication must be taken into consideration and the doctor that is treating you should be able to give you a better assessment.  Retin-A can cause skin irritation.  It probably would not harm the grafts.

These are the type of questions you should ask your dermatologist. Doxycycline should not impact the transplant and Retin A also should not but Retin A is an acid and it might make the area look red.