Your Skin’s First Line of Defence

The Acid Mantle, sounds like it was ripped out of the pages of a Geology textbook discussing the layers of earth’s crust.

The Acid Mantle is in fact your skin’s first line of defence and a vital component for healthy skin

The acid mantle is a thin film formed by sebum (the oil that lubricates the skin), produced by small glands on the skin called sebaceous glands and the body’s sweat. This film is slightly acidic with a pH ranging from 5.0-4.3. The acidic pH is the result of amino acids (building blocks of proteins) in sweat and the fatty acids, wax esters & triglycerides in sebum. This film sits atop the Stratum corneum, the outermost layer of skin.

The acid mantle acts as a barrier to bacteria, viruses, pollution & toxins which are attempting to penetrate the skin, preserves the good bacteria that are part of the skin’s microbiome (community of micro-organisms), and prevents the loss of moisture through trans-evaporation by forming a barrier that keeps moisture in, hydrating the skin and maintaining its integrity.

The acid mantle is an essential player in the moisture barrier that your skin relies to stay hydrated and supple.

The Acid Mantle relies on an acidic pH to maintain itself, and there are a number of factors that can disrupt the acid mantle. Low relative humidity typical of winter time, harsh or alkaline cleaning products, over-exfoliation, temperature extremes (indoor heating or cooling and then going into humid air outside), and certain chemicals like sodium lauryl sulphate a foaming agent which can be harsh on skin.

The breakdown of the act mantle can lead to dryness, itchiness, flaking, redness, irritation, increased sensitivity to ‘bad’ bacteria and environmental stressors, more acne prone skin, and lead to conditions like eczema, psoriasis, dermatitis & inflammation.

There are a few ways to protect against destroying the acid mantle:

1. One of the most effective ways is to avoid unnecessary over-exfoliation. Limiting exfoliation with mechanical or chemical exfoliants to once or twice a week will go along way to preventing an imbalance in the acid mantle. Another trick is to avoid physical exfoliants like ground up apricot and instead to use chemical exfoliants like Alpha Hydroxy Acids (AHA), hyaluronic acid & sodium hyaluronate and to limit how frequently they are used.

2. Another powerful way to protect the acid mantle is to use skincare products that are pH balanced to be slightly acidic. The squeaky clean feeling you get from certain cleansers is an indication that the products are alkaline and are disrupting the act mantle.

Myufull’s skincare line available at Oo Spa is formulated to be slightly acidic to match the natural pH of skin. Myufull products also contain acid mantle nourishing ingredients like sodium hyaluronate, hydrolyzed collagen, and snow mushroom (probiotic ingredients are particularly effective at stabilizing the acid mantle)


It’s clear, for healthy skin protecting the acid mantle is essential!


Written by: Tino Calenda, January 12, 2023



Diaz, A. (2019). How to repair your skin’s moisture barrier after over-exfoliation. The Klog. Retrieved on January 12, 2023, from:

Surber, C. Humbert, P. Abels, C. & Maibach, H. (Aug 20, 2018.). The acid mantle: a myth or essential part of skin health? Current Problems in Dermatology. 54:1-10. Doi: 10.1159/000489512. Retrieved on January 12, 2023 from:

Week, D. (Oct 15, 2020). Understanding your skin’s acid mantle and why it’s so important. Good Housekeeping. Retrieved on January 12, 2023, from: