77% Houttuynia cordata, panthenol, no alcohol, pH-balanced for skin that reacts to things. 250ml for ₩18,000–25,000 works out cheap enough to use morning and night without rationing it, which in practice matters more than any single ingredient on the label. This is the product that carried Anua out of Korea.
What it does: takes visible heat out of skin that has been over-cleansed, wind-burned, or pushed too hard with actives. What it does not do: it will not clear cystic acne, fade a scar, or treat rosacea. Persistent breakouts and anything painful belong in a dermatologist's room rather than a shopping basket.
Worth knowing, because most roundups get this wrong: heartleaf and centella are different plants. Houttuynia cordata is heartleaf, 어성초. Centella asiatica is cica, and its isolated active is madecassoside. Both calm visible redness, and Korean sensitive-skin lines use them almost interchangeably, but if one of them has irritated you before, read the ingredient list instead of the front of the box.
The caveat is real: it is very light. Through a Seoul winter, on dry skin, it is a first layer and nothing more. I use it heavily in summer and put a cream over it from November. For a full routine around it, the sensitive and acne-prone routine is the one to read, and the sensitive picks and breakout picks pages list what pairs with it.