The prescription provided by your dermatologist
is apt for acne problem.
I would advise you to be compliant with medicines advised. Sunscreen lotions as such are not meant to treat acne but these may be helpful in preventing tanning
of face and also may aid in preventing post acne pigmentation. If your skin is blackhead
prone get them removed regularly and apply adapalene
gel over those areas to prevent these from recurring. If topical therapy alone does not work much, you might require a course of oral anti acne drugs..
Hope that answers your query. Take care.