K-Beauty Glossary
What is pH Balance?
Skin acidity (target ~4.5–5.5)
Skin's natural pH is slightly acidic — roughly 4.5 to 5.5 — which supports barrier function, microbiome balance, and active ingredient efficacy. Cleansers and products with high pH (>7) disrupt the acid mantle. Ideal skincare products are pH-balanced: around 5 for cleansers and moisturizers, lower for acids (3–4 for AHAs, ~3.5 for vitamin C L-AA) to remain active. Products can say 'pH-balanced' but that claim isn't regulated — check the actual pH if it matters to you (~strip-tested).