I have been taking 120,000 serrapeptase, quite a high dose, for quite a long time, twice daily and it has not had any noticeable effect on a scar on my face. I have upped the dosage from 80,000iu which I was using previously for quite some time and nattokinase before that. I take these for other reasons and not specifically for the scar.
That is why I suggested using DMSO and using serrapeptase/nattokinase type enzymes topically. Adding vitamin c and collagen amino acids should enhance the effect and promote rebuilding.