Covering two square meters, skin is the largest human organ. Skin consists of three distinct layers:

• The epidermis (the top layer), formed by four layers including the stratum corneum (outermost layer)
• The dermis, (the thick middle layer)
• The subcutaneous tissue (the bottom fatty layer)

The outermost layer — the epidermis or the stratum corneum — is the part of the skin that is considered the “skin barrier” and performs the skin’s primary barrier function. This layer is the body’s natural barrier to dangers like the sun’s UV light, toxins, bacteria, and allergens.[2]

Under a microscope, the skin barrier looks very much like a sturdy rock wall, with skin cells acting as the rocks and essential fatty acids and ceramides serving as the mortar or glue, keeping it all intact. In order to maintain the strength of this “rock wall”, you must nurture your skin with proper nutrients and avoid exposing it to unnecessary toxins and chemicals that could break down it’s structural integrity.

Skin microbiome: Living above and within the skin barrier is the body’s skin microbiome. This diverse group of microorganisms symbiotically defends the body from dangerous viruses and bacteria and works alongside the immune system, detecting and attacking foreign organisms. When the identity and composition of the skin microbiome is negatively altered, so is your body’s ability to protect itself. Learn more about how you can maintain a healthy skin microbiome here.

pH: Another mode of defense within the skin barrier is its pH level. Skin typically has a slightly acidic pH, which helps to keep harmful microorganisms at bay. When the skin barrier is knocked off its usual pH balance, it loses its ability to defend against environmental toxins and stressors.[3]

Not surprisingly, when any one of the factors above become compromised, the body is more prone to illness and infection. For example, if the skin barrier is damaged, the following conditions may occur:

• Moisture and water loss.
• Increased vulnerability to sun damage.
• Skin infection and irritations.
• Lowered immune system.

A direct consequence of a weakened skin barrier is increased moisture escaping from the body, causing the body’s internal homeostasis to become imbalanced and more vulnerable to infections and sensitivities.

The skin barrier also has a broader impact stemming from its connection to immunity and system-wide inflammation. Immune cells are contained throughout all three layers of skin, including the skin barrier. This allows the skin barrier and the immune system work in tandem to alert the rest of the body to infections and to modulate system-wide inflammation.

When the skin barrier is weakened, the immune system’s ability to modulate inflammation is jeopardized, causing increased inflammation, which is a precursor to many degenerative diseases. As a result, a compromised skin barrier can contribute to increased levels of inflammation in the blood which could increase the risk of a number of age-related diseases, including Alzheimer’s disease, cardiovascular disease, and diabetes.

Due to the important role that the skin barrier plays in our health, maintaining its strength is key in living a healthy and long life.

Knowing how to spot skin barrier damage is the first step in addressing the health of your skin. It’s best to identify and address a weakened skin barrier as early as possible, since prolonged damage makes it more challenging to restore the skin barrier back to health, thereby exposing the body to a higher risk of inflammation, infection, and weakened immunity. If your skin barrier is weakened, you will likely display one or multiple of the following signs:[4]

• Acne
• Dry skin or flaking skin
• Heightened skin sensitivity
• Itching
• Redness or other discolorations
• Inflammation
• Frequent infections
• Rashes

Some factors that weaken the skin barrier are difficult to control, such as pollution, humidity, and genetic skin conditions, like psoriasis and atopic dermatitis. However, there are many other factors within our control that have the potential to compromise the integrity of your skin barrier, such as:

• Retinol. Although retinol is often regarded as the gold standard in anti-aging skincare, it can do long-term damage if overused or misused. Regular retinol use can make the skin barrier thinner, and in the long run, degrade the skin’s overall health. Additionally, the long-term adverse effects of retinol on the body remains heavily debated.[5]
• The Sun. Sun damage can prematurely age the skin, making it more prone to skin cancer. It also degrades the proteins that serve as building blocks in the skin, thereby weakening and thinning skin. Called photoaging, sun damage can also make your skin appear and act older through uneven skin tone, decreased barrier function, fine lines and wrinkles, and rough or hard texture.[6]
• Exfoliants and harsh cleansers. Exfoliants and cleansers can sometimes do more damage than good by stripping away too much of that all-important outer layer of the skin that makes up the skin barrier. In the case of exfoliating, a little bit goes a long way.[7]

Fortunately, there are steps you can take to protect and fortify your skin barrier, such as:

• Limit sun exposure and use sunscreen daily. You can still have your fun in the sun without wreaking havoc on your skin. Just remember to use sunscreen with an SPF of at least 30 and consider wearing a hat to protect the parts of your body that experience the most direct sun exposure (i.e. your head, face, shoulders, and neck). It’s also a good idea to avoid the sun at peak hours, which typically occurs from 10am to 2pm.[8]
• Be gentle on your skin. The skin’s natural defenses work better if they’re not washed away. Use non-abrasive products that support your skin’s natural homeostasis, proper oil production, pH, and microbiome.
• Moisturize with quality products. Because moisturizers and cosmetic creams are designed to penetrate the skin barrier, what you apply to your skin plays a significant role in how strong your skin barrier is. To protect your skin barrier, avoid using moisturizers that contain retinol, parabens, fragrances, or mineral oil. Instead, look for products that contain hyaluronic acid and niacinamide.
• Support skin barrier function with a topical supplement. Although diet plays a major role in how we care for our skin, consuming a supplement isn’t an efficient delivery method for delivering nutrients to the skin barrier. Rather than being absorbed through the digestive system, the ingredients within topicals go directly to the skin. OneSkin’s OS-01 Topical Supplement reaches the skin barrier at the molecular level, making it ideal for skin barrier support.

• OS-01 increases barrier function by +15% in just 12 weeks. In a 12-week clinical study, researchers found that participants experienced an average of a 15% increase in barrier function, as analyzed by measuring participant’s transepidermal water loss, a key indicator of barrier function.
• OS-O1 strengthens the skin barrier, while retinol degrades it. By using a microscopic visual analysis tool to view skin that was exposed to retinol versus OS-01, OneSkin’s scientists were able to visualize the impact that retinol and OS-01 have on the skin barrier (the top layer of the skin). The skin that was treated with retinol experienced a “peeling effect”, weakening its top layer. Additionally, the cellular structure and organization was compromised with exposure to retinol, indicating that the skin’s barrier function had also been compromised. Conversely, OS-01 induced the formation of a much thicker epidermal layer (dark purple), with a more defined general structure and cellular organization, indicating that skin became thicker and more resilient with improved barrier function when treated with OS-01.

• The skin barrier, also known as the stratum corneum, is the outermost layer of skin responsible for protecting us from environmental risks like pathogens and sun exposure.
• A weak or damaged skin barrier loses its shielding capacity, leading to dehydration, infections, and skin irritations.
• We can take steps to protect our skin barrier by avoiding harsh cleansers and skin products like retinol, reducing sun exposure, and caring for our skin with proven ingredients.

References

• [1] https://www.americanskin.org/resource/
• [2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8002265/
• [3] https://pubmed.ncbi.nlm.nih.gov/30130768/
• [4] https://pubmed.ncbi.nlm.nih.gov/31454051/
• [5] https://www.ijstr.org/final-print/nov2016/How-Can-Cosmetics-Cause-Breast-Cancer.pdf
• [6] https://www.yalemedicine.org/conditions/sun-damage
• [7] https://practicaldermatology.com/articles/2020-apr/the-effect-of-cleansers-on-the-skin-microbiome
• [8] https://www.skincancer.org/risk-factors/uv-radiation/