Old stitch scars on the forehead can be significantly improved with the right treatment. Depending on whether it's a flat, depressed, or raised scar, options include microneedling, fractional CO2 laser, chemical peels, or surgical scar revision. These are safe and effective when done by a professional.
Next Steps
Consult a dermatologist or plastic surgeon for an in-person scar assessment and to get a treatment plan. In the meantime, apply silicone gel (Dermatix or ScarAway) daily to help soften the scar, and always use sunscreen over it to prevent darkening. Consult me on Practo for further guidance.