Mayo Clinic Dermatologist Reveals 5 Critical Functions Of The Skin & How They Impact Aging

Skin longevity is no longer a novel concept—it’s gone mainstream, with all the major beauty brands launching “skin longevity” collections, aimed at supporting skin structure and cellular health through key longevity pathways. It’s a development we certainly applaud. We love the idea of having smooth, glowing skin for the long-term. 

But still, we suspect there's something we’re still missing. 

According to Saranya Wyles, M.D., Ph.D., director of the Regenerative Dermatology & Skin Longevity Laboratory at Mayo Clinic, we may have been thinking about this topic from the wrong point of view. During her conversation with mindbodygreen co-founder Jason Wachob at the 2026 Revitalize summit, she explained that true skin health and longevity isn't about the end result or aesthetics at al—it's about functionality.

Here's the thing: Your skin is the largest organ in your body, and it's doing far more than just sitting there looking pretty. “The skin does five or six ideal functions, if not more,” says Wyles. It's actively protecting you, regulating your temperature, synthesizing vitamins, and communicating with your nervous system. When those functions decline, the visible signs often follow. 

As Wyles puts it: "Function begets structure." When your skin is functioning optimally, the structural benefits that we all focus our attention on—firmness, hydration, resilience—come along for the ride.

Your skin is a metabolically active, regenerative organ that plays a systems-level role in your overall health, Wyles reminds us. 

Think about it: Your skin is part of your immune defense, your thermoregulation system, and even your endocrine system (more on that later). When these processes start to decline—whether from aging, environmental stress, or lifestyle factors—the visible signs of aging often start to show up. Wrinkles, sagging, dullness? Those are ripple effects, not the root issue.

Let's start with the big one. Your skin barrier is a living, evolving shield that protects you from UV radiation, pollution, pathogens, and allergens while simultaneously keeping moisture locked in.

"The minute we start aging, our barrier, which is like a basket weave, slowly starts to open up," Wyles explained. "So that means, just at rest, you're losing water a lot easier."

Your skin produces sebum to lubricate and protect itself, an essential part of its barrier function. But that’s not all: It also secrets sweat to help eliminate waste and support microbiome balance. These aren't just byproducts—they're active functions that contribute to skin health.

To zero in on sweat: “The skin secretes toxins through your sweat,” says Wyles. 

Incorporate regular movement and/or sauna use to promote healthy sweating. Yes, this tip is dermatologist-approved.

“When you exercise, you sweat and when you sweat, you release toxins from your skin. So exercise has great implications for the skin,” she says. “And this can also be achieved by doing saunas, which is also a great way to allow your skin to release that sweat.”

Your skin absorbs topical ingredients into the upper layers of the epidermis, which then encourage cellular renewal, help protect collagen and elastin, and fortify the barrier. This is why the products you put on your skin actually matter.

Focus on fewer, well-formulated products rather than layering on everything under the sun. “It's actually very simple,” she says. Wyles uses a simple routine for day and night, aligning with the skin’s own repair and defense clock.

Your skin houses nerve endings that detect pain, pressure, and temperature. It's your early warning system for danger and a key player in nervous system regulation.

Research shows that aging leads to decreased epidermal nerve density4, particularly in facial skin. This decline affects not just tactile perception, but also sweating and thermoregulation — showing how interconnected these skin functions really are.

Here's one that might surprise you: Your skin is essentially an endocrine organ. It synthesizes vitamin D6 in response to UVB exposure, which impacts immune health, bone health, mood, and other longevity pathways.

During sun exposure, 7-dehydrocholesterol in the skin absorbs UVB radiation and is converted to previtamin D3. Most cells and organs in the body have vitamin D receptors, making this function far-reaching in its effects.

Aim for balanced sun—and safe!—exposure. Be sure to wear sunscreen daily, avoid peak hours in the sun, and never sunbathe for sport. If you do need to spend hours outside, be sure to utilize UFP accessories (like hats or clothing) and sunglasses. 

Supplementation is another route to improve vitamin D levels. One study found that research participants who took a modest level of oral vitamin D supplementation (1,000 IU of D3 taken daily) experienced an increase in vitamin D blood levels—whereas participants who chose to rely on sunlight exposure, on the other hand, had no significant increase.

Blood testing can help determine if your levels are in an optimal range, so you can personalize your intake accordingly. 

Let's bring it back to Wyles' core thesis: "Function begets structure."

When your barrier is strong, your skin retains hydration and looks plump and dewy. When circulation is healthy, your complexion has that natural glow and the skin cells receive critical nutrients. When cellular activity is optimized, collagen production is supported and skin maintains its firmness and elasticity.

Skin health isn't about chasing a wrinkle-free reflection. It's about supporting the essential functions that keep your skin, and by extension, your whole body, resilient and thriving.