What is the skin barrier function?
Your skin has a number of important jobs, and its number one role is to act as a protective barrier. In particular the top layer of the skin, the stratum corneum, is responsible for:
- holding onto water and other essential substances in your skin
- keeping out things you don’t want to enter your body like irritants and microorganisms
The stratum corneum is technically dead, and it’s only 10-40 microns thick, but it’s incredibly good at keeping up this barrier function. It’s made up of flattened dead skin cells known as corneocytes which are surrounded by oily lipids: fatty acids, cholesterol and ceramides. The corneocytes sit in the lipids much like bricks in mortar.
What happens when the barrier function is compromised?
Most of the time the stratum corneum does its job without much effort on your part. But sometimes this powerful little barrier doesn’t work as well as it should, and that’s when you’ll notice things going a bit wrong. For example, you might see:
Dry, dehydrated and flaky skin
The stratum corneum keeps itself hydrated in two main ways: its oily lipids form a film that stops water from evaporating, and it holds onto water like a sponge via the natural moisturising factor (NMF). If either the lipids or the NMF are disrupted, water evaporates faster and you end up with dry, dehydrated, flaky skin that feels tight and irritated. Dehydrated skin also doesn’t renew itself properly, so you might notice cracking and roughness too.
If the barrier isn’t functioning properly, it isn’t just letting things out… it’s also letting things in, and not all of them are good. In particular, irritants can get into your skin and cause redness, burning and itching. Even if you’ve used a product without issues before, using it on a weakened barrier can result in irritation.
A disrupted barrier is more prone to inflammation, which is one of the main contributing factors to acne and breakouts.
If you let your barrier suffer, you can end up with serious skin conditions like atopic dermatitis, psoriasis or infections.
How can I protect my skin?
So now that you know the importance of a well-functioning barrier, you’ll want to know how to keep it working effectively. We have you covered! Your skin’s barrier function can be influenced by several factors: age, environment, genetics, diet, and beauty products. While you can’t do much about your age or genetics, there are a few things you can do to nurture your skin.
The two most important things that keep your skin barrier healthy are maintaining the right level of skin hydration and keeping the lipids in the stratum corneum in the right quantity. To that end, you can:
Have a gentle cleansing routine
Surfactants, the key ingredients in cleansers, remove the protective lipids from your skin along with the dirt and grease you’re trying to remove. In particular, soaps and sodium lauryl sulfate (SLS) are particularly stripping. Hot water also rinses away lipids as well as your hydrating NMF components, so keep the heat down even when it’s the dead of winter. Alkaline cleansers with a pH over 7 can also mess up your barrier, so avoid those. Keep cleansing to a minimum and stick to gentle cleansers.
Don’t exfoliate too much
Gentle exfoliation will help keep your skin healthy, but overexfoliation will leave your skin vulnerable and raw. Avoid using scrubs with rough particles on your face. Instead, use a scrub with soft grains or round beads that feel like they’re buffing your skin rather than scratching it. Introduce chemical exfoliants into your routine slowly, and listen to your skin – if it feels more sensitive than usual, skip exfoliating.
Limit your exposure to harsh weather
Extremes in weather can wreak havoc on your skin. Very hot weather can exacerbate irritation, while very cold weather makes your skin less flexible and more prone to injury. Exposure to wind and sun will damage your skin, and dry air (such as in an air conditioned office) can cause dehydration.
Eat a healthy, balanced diet containing essential fatty acids
There isn’t much research around the effect of diet on skin barrier function, but essential fatty acids in the skin have to be obtained through food, so make sure you’re eating enough omega-3 and 6.
Use barrier-repairing ingredients in your skincare
There are some ingredients in skin care products that can help restore your skin’s barrier function. Qlabo Eauphoria contains niacinamide (vitamin B3), which is particularly good at strengthening your skin. It also has both low and high molecular weight hyaluronic acid, which gives longlasting hydration to counteract the loss of moisture-holding NMF components from cleansing.
Qlabo Collagenerous is also a great choice for nourishing your skin, with humectant ingredients like hyrolysed collagen and trehalose to hold onto water, and dimethicone to seal it in. Bonus: it also contains yeast beta glucan which can help reduce oxidative stress caused by environmental damage.
- GK Menon, GW Cleary & ME Lane, The structure and function of the stratum corneum, International Journal of Pharmaceutics 2012, 435, 3-9.
- D Markland, Healthy Skin Starts with a Healthy Barrier, Dermascope(accessed May 1 2017)
- PM Elias, Skin barrier function, Current Allergy and Asthma Reports 2008, 8, 299-305.
- KP Ananthapadmanabhan, DJ Moore, K Subramanyan, M Misra & F Meyer, Cleansing without compromise: the impact of cleansers on the skin barrier and the technology of mild cleansing, Dermatologic Therapy 2004, 17, 16-25.
- ZD Draelos, Concepts in skin care maintenance, Cutis 2005, 76, 19-25.
- KC Madison, Barrier function of the skin: “la raison d'Être” of the epidermis, Journal of Investigative Dermatology 2003, 12, 231-241.