The acid mantle: Your skin’s first line of defence

The acid mantle is your skins first line of defence. The skin is made up of three layers. Each layer works to protect our body from microbes and the environmental pollutants, regulate your body’s core temperature, and facilitate those all-important sensations of heat, cold, and touch. But the science behind your skin’s sensory power doesn’t end there!

On your skin’s surface, there’s another very fine, slightly acidic layer of film called the acid mantle. This thin layer has a crucial role to fulfil. Its your skins first line of defence.

What is the acid mantle?

The acid mantle is more than just a buzzword that’s bandied about by beauty brands. As the outermost, thinnest, and seemingly “invisible” ‘fourth layer’ of the skin, it  is officially your skin’s first line of defence.

This thin film that on the surface of the skin making your skin a slightly acidic pH and ensures healthier function, appearance, and condition.

What’s the acid mantle made of?

The acid mantle is made mostly of sebum.  This natural oil is generated and secreted by the sebaceous glands of the skin. Sebum is also found in your sweat.

The sebum itself is a mixture of water, lactic acid, urocanic acid, fatty acids, and pyrrolidine carboxylic acid. When these combine with amino acids it forms this slightly acidic and suitably protective mantle.

Despite being mostly acidic and rather scary-sounding, the contents of the acid mantle are friendly secretions that have several very important jobs to do.

Why is the acid mantle important?

The acid mantle may be extremely thin but it forms a hardy barrier on the skin to keep bacteria and other toxins out of the body where they belong.

There’s so much more to the acid mantle than keeping bacteria and other toxins at bay. It also prevents moisture loss, reduces skin sensitivity.

The mantle maintains the skin’s pH, which can directly impact the appearance and texture of the skin if it becomes too alkaline or too acidic.

It also actively kills bacteria to make the skin less susceptible to skin conditions, like acne and even skin diseases.

The acid mantle protects and preserves the microbiome of the skin too. The microbiome is a delicate balance of protective microorganisms (including good bacteria, viruses, and fungi) that live on the skin.

Could this be a myth?

For so long the mere presence of the acid mantle was the subject of much debate. Many questioned whether the acid mantle was a myth or an essential part of skin health.  However, 90 years ago  German scientists Heinrich Schade and Alfred Marchionini coined the term and uncovered the significance of this thin but perfectly formed layer of protective acid.

The term ‘acid mantle’ stuck, and since then much work has been done to broaden our understanding. We now have a clearer understanding of skin pH and r the biochemical processes that create the acid mantle.

The Naked Chemist explains more about the importance of your skin’s pH and how the acidity of the mantle protects your skin.

“If your skin is healthy, it should have a pH of around 5.5 – this will register only slightly acidic and conjures up desirable adjectives such as ‘plump’ and ‘glowing’. It really is the epidermal sweet spot, so to speak.

But did you know there is a good reason why your skin is slightly acidic?

It is because pathogenic bacteria thrive under alkaline conditions.

This is why your skincare products must be formulated without strong astringents.  They have a real tendency to upset the delicate microflora and can throw your acid mantle of balance.”

With our focus firmly on spring cleaning the skin, digging deeper into the science behind this incredibly powerful sensory organ is a must for developing a skincare routine that works not just now but in the months ahead.

When your acid mantle is damaged your skin is more prone to infections, acne, dryness and eczema.

Restoring your skin’s acid mantle is vital for keeping your skin looking, feeling, and functioning at its very best.

Discover our conscious skincare routine that helps you to do just that right here.