I don't use Mederma because of the paraben preservatives, but the active ingredient is onion extract. Believe it or not, I'm having good results taping garlic to the scar on my lip when I'm just hanging around the house.

If they're fresh scars, they need to be out of the sun for a year. I never bothered with scars on my body, and I'm not bothering with the one on my chin, which is pretty well hidden and mostly shaded by my jaw line anyway. It's an enormous PITA with the one on my lip, either putting a band-aid on it or a big white dollop of sunblock, EVERY time I go outside, even for a few minutes to hang the laundry etc.

Also you probably know that wounds need to be kept moist until they're completely closed. Never let a scab form if you can help it. There are a lot of options - Second Skin and petroleum based ointments are popular, but it seemed to me with my facial wounds that there was a point when the petroleum was really inhibiting healing. I dressed my recent incision with raw honey under a non-stick/Tegaderm pad and it healed really fast, better than with anything I've tried before, but because it's directly under my bra and HRM straps, I think I'm going to have a pretty good scar just because of the unavoidable rubbing.