In the Medical Aesthetics industry, it’s important to understand the key elements that comprise skin structure, because patients and clients may turn to Medical Aesthetics to help them with the health, condition, and appearance of their skin. Two of the essential elements that determine skin condition and appearance are collagen and elastin. 

These two proteins each play a vital, yet distinct, role in the skin ecosystem. Let’s take a closer look at how they are different, what they do, and how they impact the work that you do for patients and clients.

Collagen: the glue.

Collagen is the most abundant protein in the body, accounting for about one third of all protein composition. It is one of the major building blocks of bones, skin, muscles, tendons, and ligaments. Collagen is also found in many other body parts, including blood vessels, corneas, and teeth.¹

Collagen’s primary function is to hold cells together and give body parts their structure. There are different types of collagen for different body parts and functions. Type I, which comprises 90% of all collagen, is tightly packed and provides structure, support, and firmness to skin and bones. Type II collagen is made of more loosely packed fibers and helps cushion body joints. Other types of collagen give structure to organs and arteries and help with skin filtration.¹

Collagen’s hard, insoluble composition makes it strong, flexible, and difficult to break. Type I collagen is, gram for gram, stronger than steel.² It’s important to note that here we are talking about endogenous, or naturally occurring, collagen—the kind your body produces itself. Collagen supplements, creams, fillers, wound dressings, and cellular membrane implants are different kinds of exogenous, or externally introduced, collagen.²

As we age, our body’s ability to produce collagen becomes less efficient, and collagen production and retention decreases over time.³ For women, the onset of menopause coincides with a dramatic slowdown in collagen production.²

Other factors that decrease collagen production and quality include sun damage, smoking, and eating too much sugar and refined carbohydrates. Sugar interferes with collagen’s ability to repair itself.¹

Now, let’s discuss another vital component of skin structure, elastin.

Elastin: the spring.

Elastin is a key connective protein that provides resilience and elasticity to tissues and organs. Elastin is roughly 1,000 times more flexible than collagen. The main function of elastin is the elasticity of tissues. It is the dominant protein in extensible tissues—tissues that need to expand and contract—and is primarily present in the lungs, aorta, and skin.⁴

Elastin is what helps skin snap back into place after it is moved or stretched. Because there are so many different facial muscles and movements, our facial skin is constantly stretching, recoiling, expanding, and contracting. Smiling, frowning, talking, squinting, widening or narrowing of the eyes—all of these movements, and the subsequent return to a “resting” face, show elastin in action. 

Skin aging, both intrinsic and extrinsic, results in wrinkled skin with decreased elasticity. In the skin, the aging process is disruptive to the elastic fiber network, resulting in reduced tissue compliance and rebound, structural damage, and impaired homeostasis. In addition to damage to the elastin network, aging also disrupts levels of other major skin components such as collagen, hyaluronic acid, glycosaminoglycans, integrins, and laminin. Elastin is particularly vulnerable for several reasons. Elastin and elastic fibers are unique in that there is very low and slow turnover. In fact, in skin, the overall half-life of elastin is similar to the human lifespan!⁵

These long-lasting fibers suffer from years of repeated mechanical and environmental wear and tear, and it is unlikely that these proteins and fibers will be appreciably replaced. The inability of the skin to naturally replenish or repair elastic fibers has resulted in the majority of current therapies being aimed at protecting elastin fibers rather than replacing them.⁵

Elastolytic enzymes called elastases, which arise from disease, sun exposure, free radical damage, inflammation, and other conditions, degrade elastin fibers. Disruptions to the elastic fiber network occur in two main ways: first, the elastic fibers shorten and fragment; and second, damage accumulates to the protein through modification of aspartic acid residues, calcium and lipid accumulation, and glucose-mediated crosslinking.⁵

Although elastin has very low turnover, its production decreases after individuals reach maturity and it is susceptible to damage from many factors. With advancing age and exposure to environmental impacts, elastic fibers degrade. This degradation contributes to the loss of the skin’s structural integrity; combined with subcutaneous fat loss, this results in looser, sagging skin, causing undesirable changes in appearance. The most dramatic changes occur in chronically sun-exposed skin, which displays sharply altered amounts and arrangements of cutaneous elastic fibers, decreased fine elastic fibers in the superficial dermis connecting to the epidermis, and replacement of the normal collagen-rich superficial dermis with abnormal clumps of solar elastosis material. Disruption of elastic fiber networks also leads to undesirable characteristics in wound healing, and the worsening structure and appearance of scars and stretch marks. Identifying ways to replenish elastin and elastic fibers should improve the skin’s appearance, texture, resiliency, and wound-healing capabilities. However, few therapies are capable of repairing elastic fibers.⁵

The key difference between collagen and elastin.

The main difference between collagen and elastin is that there are more ways to address collagen deficiencies. Between supplements, creams, and exogenous collagen derived from human or animal sources,² plus procedures like PDO Threading that can help stimulate endogenous collagen production, the technology is farther along when it comes to restoring skin firmness and tightness, the primary function of collagen.

There are many interventions to improve levels of collagen in the skin, but no established treatments that increase production of elastin. This is because elastogenesis, or elastin production, is a complex process that involves the crosslinking of tropoelastin monomers and microfibrillar proteins to produce elastic fibers. This process is much more difficult to stimulate and regulate than collagenesis because of the multiple steps involved in the assembly process. Procedures such as injections of collagen and hyaluronic acid to rejuvenate skin have been developed, but there are currently no approved devices to introduce functional elastin into the skin.⁵

Since there are less available options to restore or reproduce elastin, it’s especially important to preserve and protect endogenous elastin. Protecting skin from UV damage and environmental pollutants and avoiding sugars or refined carbohydrates that can degrade existing elastin production ⁵ may aid with elastin preservation. 

Collagen and elastin matter.

Similar to the roles collagen and elastin play, your patients may turn to you as a resource to help them improve their skin condition and appearance, especially when it comes to the signs of skin aging like wrinkles, fine lines, and sagging or drooping skin. 

Understanding what these distinctively different, but vitally important proteins do for the skin may help you better understand how to best serve your patients and clients and meet their Medical Aesthetic needs.