Is there a Korean pharmacy in Seongsu?
Yes. Optima Wellness Museum (OWM) Seongsu is a Korean pharmacy at 1–3F, 48 Seongsu-il-ro 4-gil, Seongdong-gu, Seoul.
It is open daily, 10:00–21:00. Pharmacists there can help with skincare, supplements and over-the-counter medicine.