Selenium (Thermal Water Mineral)
Also known as: Selenium-Rich Thermal Water, La Roche-Posay Selenium Thermal Spring Water
The trace mineral La Roche-Posay built a brand around. Real science, modestly applied.
What It Does
Deep Dive
Selenium is an antioxidant trace mineral that appears naturally in certain French thermal spring waters — most famously the 100-metre-deep spring at La Roche-Posay, whose water carries exceptionally high selenium concentrations (53–60 µg/L). Topically, selenium has documented anti-inflammatory and free-radical-scavenging effects, which is why La Roche-Posay's entire therapeutic positioning — Toleriane, Cicaplast, Thermal Spring Water spray — orbits this one mineral. The benefits are real but modest: it is a supportive ingredient, not a headline active. Best understood as why the brand works for post-procedure and reactive skin, rather than a standalone miracle.
Sources
- [1]Selenium-rich thermal water and skin inflammation