According to the package:
For women concerned about visible pores –
This essence blends into the cheeks where concern about visible pores lies, firming the skin and making the pores less visible
•Astringent EX (firming component) compound
•Pore smoothing powder compound
•Smooth, non-greasy feel
•Light scent and colorless
•Apply Sofina Pore Zone Care Essence daily, in the morning and at night, after caring for the skin with lotion, milk or cream
•With the fingertips, smooth a grain-sized amount of the essence deep into problem pores
This claims to be a serum that you use after your basic skin care, but I mainly use it as a primer.
I didn't see any permanent effect in reducing the size of my mores, but when I use it as a primer before my makeup, it visibly reduces the size of the my pores and my foundation application appears to be smoother.