I was dermarolling my forehead and now it's been really red for 3 days and hasn't gone down . it dosent hurt can i put neosporin on it?

Skin irritation: The procedure you did caused the outer layer of skin, the epidermis, to be removed, resulting in the redness you are experiencing. It will take a few weeks more to regrow. Applying Neosporin may act as a barrier to prevent infection, but it may delay the regrowth process. I'm the abscence of any pus or oozing from the skin- signs of infection- I would just keep the area clean and dry.