What Is a 'Beauty Spring' (Bijin-no-yu)? | Why Metasilicic Acid Makes Skin Glow

Metasilicic Acid and Skin Benefits

Metasilicic acid (SiO₂) is one of the officially recognised therapeutic spring components under Japan's mineral spring analysis guidelines. Springs containing 50 mg/kg or more meet the threshold. It is associated with promoting collagen synthesis, moisturising skin, and softening the stratum corneum. Volcanic regions such as Gunma and Nagano are particularly rich sources.

Three Spring Types Noted for Skin Benefits

• Bicarbonate spring: Cleansing action that removes dead skin cells — known as the "cleansing spring"These springs are said to have a cleansing effect on the skin's surface. This gentle action is why they are often called “cleansing springs,” leaving the skin feeling smooth and refreshed.
• Chloride spring: A salt film on the skin prevents moisture loss, leaving skin silkyThe salt components in these springs form a thin film over the skin's surface. This natural barrier helps prevent moisture from evaporating, providing a powerful moisturizing effect that leaves skin feeling supple and hydrated.
• Sulfate spring: Known as the "wound spring" or "beauty spring" — sulfate components aid skin regenerationTraditionally known as the “wound spring” or “beauty spring,” these waters contain sulfate components. Cuts and dry skin are listed among the indications for sulfate springs.