What is the skin barrier and what does it do?
How does the skin barrier maintain balance?
What happens when the skin barrier is weakened?
- Moisture and water loss: When your skin barrier is weakened, more water can escape from your body through the surface of your skin. This can disrupt your bodyβs internal homeostasis and make you more vulnerable to infections and sensitivities.
- Increased vulnerability to sun damage: While wearing sun protection is critical, your skin does have some natural UV defenses of its own. However, these defenses are severely compromised when the barrier is weak, which means your skin is more vulnerable to DNA damage caused by UV radiation.
- Skin infection and irritations: As a physical shield against external pathogens and irritants, the skin barrier keeps the entire body protected. Micro-injuries in the skin barrier allow external irritants to enter the body, leading to everything from minor skin irritation to major infections.
- Weakened immune system: All three layers of the skin contain immune cells. This allows the skin barrier and the immune system to work in tandem, alerting the rest of the body to infections. A weak barrier makes it difficult for the immune system to modulate inflammation, causing an increase in systemic inflammation, which is a precursor to many age-related diseases, including Alzheimerβs disease, cardiovascular disease, and diabetes.
How can I tell if my skin barrier is weakened?
- Acne or very oily skin
- Dry or flaking skin
- Heightened skin sensitivity
- Itching or rashes
- Redness and inflammation
- Frequent infections [4]
What weakens the skin barrier?
- Retinol: Although retinol is a beloved anti-aging ingredient, it can severely degrade the integrity of the skin barrier β leading to redness, irritation and peeling.[5] In fact, in a study conducted by OneSkin scientists, we observed that skin that was treated with retinol experienced a βpeeling effectβ that weakened its top layer. Additionally, retinol compromised cellular structure and organization, indicating that the skinβs barrier function had also been negatively altered. [6]
- Sun exposure: UV radiation degrades the proteins that serve as skin building blocks, weakening and thinning skin over time. Sun damage can also make your skin look and act older β leading to decreased barrier function, fine lines and wrinkles, and rough texture.[7]
- Intense exfoliants. Exfoliants can sometimes do more harm 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 goes a long way.[8]
- Harsh cleansers: Face washes that contain harsh detergents like sulfates strip away the lipids that act as the mortar in the skin barrier, creating vulnerabilities that can lead to increased dryness and sensitivity.
- Hot Water: You might love a scalding-hot shower, but your skin barrier doesnβt. Very hot water melts the lipids that keep your skin barrier strong, leading to redness and dryness.
How can I protect my skin barrier?
- Limit sun exposure and use sunscreen daily. 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. Itβs also a good idea to avoid the sun at peak hours, which typically occur from 10am to 2pm.[9]
- Be gentle. The skinβs natural defenses work better if theyβre not washed or scrubbed away. Use non-abrasive products that support proper oil production, pH, and microbiome balance.
- Use quality products. What you apply on your skin plays a significant role in how strong your skin barrier is. To protect your skin barrier, avoid products that contain retinol, parabens, or fragrances.
- Support skin barrier function with the OS-01 peptide. In a 12-week clinical study, OS-01 FACE, was shown to increase barrier function by +15%, as shown by measuring participantsβ transepidermal water loss, a key indicator of barrier function. In the lab, our scientists also found that OS-01 FACE 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. [6]

- The skin barrier, also known as the stratum corneum, is the outermost layer of skin responsible for protecting us from environmental threats like pathogens and UV radiation.
- A weak or damaged skin barrier loses its shielding capacity, leading to dehydration, infections, and skin irritations.
- This can show up visibly as redness, breakouts, irritation, and heightened skin sensitivity.
- You can take steps to protect your skin barrier by avoiding harsh cleansers and retinol, reducing sun exposure, and caring for your skin with OS-01, which has been shown in clinical studies to improve barrier function. .
- https://www.americanskin.org/resource/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8002265/
- https://pubmed.ncbi.nlm.nih.gov/30130768/
- https://pubmed.ncbi.nlm.nih.gov/31454051/
- https://www.ijstr.org/final-print/nov2016/How-Can-Cosmetics-Cause-Breast-Cancer.pdf
- Zonari, A., et al. Senotherapeutic peptide treatment reduces biological age and senescence burden in human skin models. Npj Aging, 9(1), 1-15. 2023.
- https://www.yalemedicine.org/conditions/sun-damage
- https://practicaldermatology.com/articles/2020-apr/the-effect-of-cleansers-on-the-skin-microbiome
- https://www.skincancer.org/risk-factors/uv-radiation/