I had this scab and by mistake ripped it out. Will Mederma really work on scars?

Scabs BAD. The best thing you did was rip the scab off. Mederma may provide the wound optimal conditions to heal, but it is the way your body heals wounds that will ultimately determine how the scar will turn out. A scabs is the body's way to protect a wound while healing. But esthetically, a scab will result in a gap between skin edges that eventually becomes visible. Use antibiotic oint keep clean no scabs.