I'm using PurCellin oil(Bio-Oil) on my hernia scar (it is huge). I have seen a slight improvement over the past 30 days. It is inexpensive, $10, and I got it at the local pharmacy.
I think I may eventually see a plastic surgeon to get it reduced it is so bad.
I used Mederma on my ankle scar and it worked so-so. The key is to hit the stretchmark or scar very early.