I am two weeks post-op. My sutures were removed on day 10. My donor site is closed completely. Is it OK to start using something e.g. Mederma, on it? Thanks.

Yes you should be applying something to your scar. You actually should have been applying neosporin to your donor scar all along. But by all means, start using either neosporin or Mederma or, as I did, buy an aloe vera plant and slit it open and get the juice out of it and apply it to the scar. The Indians used aloe vera many years ago for cuts and scars. It seems to help with the itching.