The Low-pH Cleanser Edit

The "squeaky clean" feeling after washing your face is the sound of your acid mantle being disrupted. A healthy skin barrier sits at pH 4.5–5.5; most drugstore foaming cleansers run pH 9–10 and strip it. The low-pH cleanser movement — pioneered by COSRX in Korea around 2014 — re-set the category by formulating gentle surfactants at physiological pH. Every cleanser here tests at pH 5.5 or lower, foams properly, removes sunscreen, and leaves skin calm rather than tight. Sensitive skin, barrier-compromised skin, and anyone who uses actives needs one of these.