is the spot raised or is it flat?
I've used Retin-A for treating pimples and it has worked great. I started with very small amounts initially and my skin started peeling and turned red the very next day. But after about a week, my skin adjusted and I started applying it a bit more generously. It helped reduce my acne significantly. I have a brown skin tone so I get dark brown spots, not red. It did help to lighten some of the old brown spots from previous breakouts. The only complaint is that my acne returns full force if I stop the retin-A even for a few days.I have .025 cream. I'm applying a small layer to my foot for the first three days to see how it reacts. I put some on two hours ago and noticed nothing so far.
Are you claiming it healed your old red marks? I have a feeling it will do nothing but potentially make things worse. The only reason I'm doing this is because I'm desperate and look like a freak.