04/12/2025
In 1928, two German dermatologists coined the term “acid mantle” and showed that the skin’s natural acidity is its primary defence against bacterial invasion. By the late 1930s their work had already linked alkaline pH shifts to pathological microbial overgrowth and impaired barrier function, while proving that the best therapeutic preparations leaned towards the acidic.
Today, we understand far more about pH. The acid mantle provides a slightly acidic environment that favours beneficial organisms. In return, those microbes reinforce immunity, compete with pathogens and actively contribute to surface acidification.
Disrupt that pH and this symbiosis collapses, commensals struggle, opportunists thrive and the whole ecosystem tips into dysbiosis.
To maintain a slightly acidic environment benefits acne, atopic dermatitis and ageing because it restores microbial homeostasis alongside barrier function.
The science has been clear for almost a hundred years, yet the industry is still hellbent on disrupting the defences that nature created.
The acid mantle and its pH level matter. They formulate the first line of defence and as such deserve to be respected.
The science was settled in 1928. When will the industry catch up?
Maria ✨
