UNDERSTANDING UV PROTECTION: MECHANISMS, REGULATIONS, AND SKIN HEALTH
By Dr. Harry Sarkas, Chief Scientific Officer
UV protection is one of the most powerful tools in modern skincare, grounded in decades of biological research and reinforced by regulatory oversight. Yet despite this strong foundation, the conversation around SPF is often overcomplicated by the very science that supports it. Understanding how UV filters work and how they are tested helps clarify their essential role within a comprehensive skin health strategy.
At its core, the principle is straightforward: daily UV protection preserves the biological integrity of the skin. As awareness of preventive dermatology continues to grow, this pillar of skin health has never been more important. Up to 80% of premature skin aging is attributed to sun exposure, and skin cancer remains the most common—and one of the most preventable—forms of cancer.
At the same time, the US sun care segment is projected to grow by 3.1% reaching $3.7B in 2026, while skin care and color cosmetics are expected to reach $27.7B and $21.1B, respectively. As innovation accelerates, understanding the science and regulatory framework behind UV protection is essential for both brands and consumers – so that we give sufficient strategic attention to the single most effective preventative tool available and, ultimately, overcome barriers to adoption.
The Biology of UV Damage
To understand how UV protection works, we must first understand how ultraviolet (UV) radiation interacts with skin.
UV radiation affects the skin at multiple depths and through multiple mechanisms, depending on wavelength. These include DNA damage, oxidative damage through the formation of reactive oxygen species (ROS), immunosuppression, and of course erythema, with the associated damage to the cellular matrix.
With respect to ROS and its downstream consequences including, inflammation, uneven pigmentation, barrier disruption, structural protein degradation, and cumulative DNA damage, as well as skin aging, these mechanisms are primarily caused by UVA. UVB is primarily responsible for erhythema, or what we call the common sunburn. Direct DNA damage and immunosuppression can be caused by both UVA and UVB.
Over time, these biological processes also cause cumulative damage that manifests as fine lines, loss of elasticity, hyperpigmentation – what we commonly call “photoaging” or “premature skin aging” – as well as an increased risk of skin cancer. With respect to skin cancer, per the FDA 2019 tentative final monograph, no appropriate biological action spectrum for UVA radiation damage has been universally accepted.
When consumers seek “anti-aging” interventions, they are often attempting to correct the downstream consequences of years of UV exposure. Prevention, in contrast, interrupts these processes before they compound. That is the biological value of daily UV protection.
Mechanisms of UV Protection
As information around the impact of UV continues to emerge, comprehensive UV coverage across all wavelengths is critical to give consumers the most broad coverage over damaging wavelengths. Consistent daily use of broad-spectrum UV protection remains one of the most evidence-backed strategies for maintaining healthy skin across all skin types and tones.
Effective UV protection is designed to prevent both short-term (e.g. sun burn) and long-term (e.g. DNA) damage. Broad-spectrum SPF products limit the amount of ultraviolet energy reaching viable skin cells. Reducing this upstream UV exposure prevents UV-induced DNA damage, decreasing cumulative mutations that may contribute to skin cancers over time. This also helps to preserve the integrity of collagen and elastin, supporting skin firmness and elasticity as skin ages, and helps maintain barrier resilience and reduce chronic inflammation and hyperpigmentation.
FDA Regulation, and Requirements for SPF Products
In the United States, SPF products are regulated by the U.S. Food and Drug Administration (FDA) and classified as monographed, over-the-counter (OTC) drugs, not as cosmetics. This distinction subjects sunscreen-containing products to rigorous safety and efficacy standards, whether they are intended for recreational use at the beach, or in a daily use sunscreen-containing cosmetic like an SPF-infused foundation or skin tint.
SPF value determination requires standardized in-vivo testing on human subjects to measure protection against UV-induced erythema (redness). Broad-spectrum claims must be supported by additional testing demonstrating adequate UVA protection, currently measured through critical wavelength testing.
SPF-containing products must go through labeling requirements (including approved active ingredients, usage directions, and warnings) that match SPF testing results and are tightly controlled to ensure consumers receive accurate and reliable information.
Behind every SPF claim is a structured scientific validation. In an industry where trust is paramount, this regulatory framework provides essential credibility and consumer confidence.
The Future of UV Protection
SPF values indicate protection against UV radiation (primarily determined by UVB radiation), and most products in the U.S. now offer broad-spectrum protection against both UVA and UVB rays, which is consistent with recommendations from the American Academy of Dermatology.
That being said, daily use depends on more than efficacy alone. Aesthetics, tolerability, and user experience will ultimately drive daily adherence – which means texture, finish, and compatibility with skin tone and type all come into play and are central to driving long-term outcomes. Zinc oxide, for example, is a globally-approved, broad-spectrum sunscreen active often preferred for sensitive skin due to its strong tolerability profile. Historically, aesthetic challenges limited its appeal, which is a challenge we took on when we invented our Active Stress Defense™ technology suite, including Kleair™, which significantly improves Wearability and inclusivity across skin tones and product formats.
With the undeniably positive impact that UV protection has on skin and overall human health, the guiding principle becomes straightforward: the best UV protection product is the one that will be used every day. As technologies continue to evolve, brands that lead with innovation, product experience, and their end-consumer in mind will be best positioned to deliver meaningful health and beauty benefits for years to come.