Hi lybrate-user,
If the scar has completely healed, you can start using Mederma for 3-6 months.
Scars can make any skin look less pleasant. But the good news is that, there are many treatments available for scars. Depending on your condition, there are medications available which can be locally applied. Further there are treatments like peels, dermaroller and RF therapy which can lead to significant improvement in appearance of scars.