Your skin does more than cover your body. It helps regulate your body temperature, shields you from harsh environments and keeps moisture in. As you get older, your skin can lose its natural ability to protect itself. The result is often dryness, irritation or increased sensitivity.

One of the biggest changes in aging skin is something called transepidermal water loss. This happens when your skin can no longer hold on to moisture the way it used to. We talked CU Medicine dermatologists Dr. Whitney High and Dr. Carla Torres-Zegarra to better understand what happens to the skin barrier over time and how you can take steps to protect it.

What is the skin barrier?

The skin barrier is the outermost layer of your skin, called the stratum corneum. It acts like a shield. It keeps harmful things out and holds moisture in. When the skin barrier is strong, your skin feels smooth, hydrated and comfortable. When it is damaged or weak, you may notice dryness, redness or stinging when you apply products.

Transepidermal water loss happens when water escapes from the deeper layers of your skin into the air. Some level of water loss is normal, but too much means the skin barrier is not doing its job.

“Your transepidermal water loss goes up every year after the age of 18,” says Dr. High.

Over time, things like aging, sun exposure and harsh skincare habits can wear down this protective layer.

“When it comes to my adult patients, I’m always seeing them on the driest day of their life thanks to transepidermal water loss.”

When and Why Does the Skin Barrier Weaken?

Most people start to notice changes in their skin barrier in their late 30s or early 40s. As skin ages, it naturally produces fewer lipids and ceramides. These are the fats that help seal in moisture and protect the surface of the skin. Without them, it becomes harder for your skin to stay hydrated.

Cell turnover also slows down with age. This means dead skin cells hang around longer, which can lead to dullness and dryness. For women, hormonal changes during perimenopause and menopause can make these effects more noticeable.

When asked about the skin barrier, Dr. Torres-Zegarra compares the layers of skin like the layers of a cake. See the video below for a deeper explanation.

[insert skin layers like cake video]

“When it comes to that first layer of the skin called the stratum corneum—or as I call it, the frosting of the cake —ideally it should prevent water loss and protect your skin from the outside,” Dr. Torres-Zegarra shares.

“A disrupted skin barrier can be felt and seen as redness, irritation, dryness of the skin and recurrent skin infections.”

These changes are normal, but knowing when they happen can help you take steps to protect your skin before dryness and irritation set in.

How to Protect and Strengthen the Skin Barrier

The good news is there are simple ways to care for your skin barrier and help it stay strong. A good routine starts with a gentle cleanser. Look for one that is fragrance free and made for sensitive skin. Harsh soaps and strong scrubs can strip away natural oils your skin needs to stay balanced.

Avoid exfoliating too often. While it may feel like you are smoothing your skin, using exfoliants too frequently can wear down the barrier and make your skin more reactive.

Daily moisture is key. Use a cream or lotion that contains barrier repair ingredients like ceramides or glycerin. These help fill in the gaps where moisture escapes and keep your skin feeling soft and supported.

Sunscreen is just as important in winter as it is in summer. UV damage weakens the skin barrier over time, even on cloudy days.

Ingredients Dr. Torres-Zegarra recommends for protecting the skin barrier:

• Ceramides
• Hyaluronic acid
• Niacinamide
• Gentle fragrance-free cleansers

In addition to gentle exfoliation and moisturizing with the right ingredients, Dr. Torres-Zegarra warns of falling into the trap of social media influencers pushing products. She shares, “Nowadays we have a ton of material on social media about different acids, toners and exfoliators. As much as they sound wonderful, you may be over-exfoliating your skin, mixing products with chemicals that shouldn’t be mixed and in turn damaging your skin barrier.”

Finally, be mindful of your environment. Cold air, wind and indoor heat all pull moisture from your skin. A humidifier at home and a richer moisturizer in colder months can help offset the effects.

As always, being around cigarette smoke and vaping can harm the skin.

Protecting your skin is not about doing more. It is about doing what works and doing it regularly.

When to See a Dermatologist

Sometimes your skin needs more support than a new moisturizer can give. If your skin feels dry, itchy or irritated no matter what you try, it may be time to talk with a dermatologist. You should also reach out if you notice new sensitivities or are unsure which products are safe for your skin.

CU Medicine dermatologists can help you understand what your skin needs and create a care plan that works for you. To schedule an appointment, visit CU Medicine Dermatology – Montview (CU Medicine Building) or call (303) 315-5085.