The Different Types and Benefits of Sunscreen

Table of Contents

• Key Points
• The Basics of UV Rays
• The Critical Connection Between Sunscreen and Skin Cancer
• Types of Sunscreen and How They Work
• The Truth About SPF Numbers
• Debunking Common Sunscreen Myths
• Daily Sunscreen Use: More Important Than You Think
• Understanding the “Full Spectrum” of Sunscreen Benefits
• Learn More About Sunscreen Uses and Benefits
• References

 

Key Points

• Sunscreen is one of the most important tools for combating the dangerous effects of the sun, including premature skin aging and cancer. 
• There are a lot of different types of sunscreen, as well as many misconceptions about effectiveness and proper use. 
• Understanding how sunscreen works, identifying quality products, and knowing how and when to apply it, are central to protecting yourself and your loved ones. 

---

Skin cancer is the most common cancer in the United States, with more than 2 million new diagnoses every year.¹ Fortunately, when detected early, it has an extremely high survival rate. The other good news is that skin cancer is highly preventable, and one of the main benefits of sunscreen is protecting against it. 

According to a recent Yahoo News/YouGov poll, despite the fact that 80 percent of people say that protecting their skin from the sun is “important,” more than 30 percent of U.S. adults say they never use sunscreen.² This discrepancy may be in part attributable to widespread confusion and misinformation about sunscreen, specifically the type of protection any given product affords. 

That is why we have put together information about what sunscreen can (and cannot) do. We specifically address myths related to SPF and other issues, like how frequently you should apply sunblock. This article will give you the tools needed to ensure you and your family are achieving adequate protection from the sun, optimizing skin health and wellness.

The Basics of UV Rays

Before we get to sunscreens, it is worth exploring what we are attempting to defend against. The sun emits three types of ultraviolet (UV) radiation³:

• UVA Rays: These are between 315 and 400 nanometers, and their intensity is consistent throughout the day. They can pass through glass and clouds, and can penetrate deep into the skin. This can cause premature aging, wrinkles, and contribute to skin cancer. 
• UVB Rays: These are 280 to 315 nanometers, and their intensity varies by time of day, season, and geographic location. UVB rays are the primary cause of sunburn and play a key role in the development of skin cancer. 
• UVC Rays: These are between 100 and 280 nanometers. UVC rays are the most dangerous type of sunlight. However, they are completely absorbed by the atmosphere, so they never reach Earth. 

While distinct in their makeup, UVA and UVB rays damage skin in several different ways:

Direct DNA Damage: UV rays have enough energy to directly alter the DNA in skin cells. UVB rays cause the formation of thymine dimers—abnormal bonds between adjacent DNA bases that distort the DNA structure. If your cellular repair mechanisms cannot fix this damage fast enough, it can lead to mutations and potentially skin cancer.⁴

Free Radical Formation: Both UVA and UVB rays generate reactive oxygen species (free radicals) in your skin.⁵ These unstable molecules steal electrons from healthy cellular components, damaging proteins, lipids, and DNA. This oxidative stress is a major contributor to premature aging and skin cancer development.

Collagen and Elastin Breakdown: UVA rays penetrate deeply enough to damage the structural proteins that keep your skin firm and elastic. They activate enzymes called matrix metalloproteinases (MMPs) that break down collagen and elastin fibers, leading to wrinkles, sagging, and loss of skin elasticity—what dermatologists call “photoaging.”⁶

Inflammatory Response: Your skin recognizes UV damage as a threat and launches an inflammatory response. This is why you get red, hot, painful sunburn after excessive sun exposure. While inflammation is part of your body’s healing process, chronic inflammation from repeated sun exposure contributes to long-term skin damage and accelerates aging.

Melanin Production: Your skin produces melanin (pigment) as a protective response to UV exposure. While this natural “suntan” provides some protection, it is actually a sign that DNA damage has already occurred. Uneven melanin production can lead to age spots, freckles, and hyperpigmentation.

The Critical Connection Between Sunscreen and Skin Cancer

Understanding the relationship between sunscreen and skin cancer is crucial for making informed decisions about sun protection. Research consistently shows that regular sunscreen use significantly reduces the risk of developing skin cancers, including melanoma, basal cell carcinoma, and squamous cell carcinoma.

A landmark Australian study followed participants for over 10 years and found that those who used sunscreen daily had a 40 percent lower risk of developing melanoma compared to those who used it sporadically.⁷ Another study demonstrated that regular sunscreen use could reduce the risk of squamous cell carcinoma by approximately 40 percent and basal cell carcinoma by about 20 percent.

The protective effects of wearing sunscreen extend beyond cancer prevention. Regular use helps prevent premature aging, including wrinkles, age spots, and loss of skin elasticity. This dual benefit makes sunscreen one of the most cost-effective anti-aging treatments available.

Types of Sunscreen and How They Work

As the name suggests, sunscreens are solutions that block UV rays. There are two main types that work to do so in different ways. 

Physical Sunscreens

Physical sunscreens contain mineral ingredients—primarily zinc oxide and titanium dioxide⁸—that act like tiny mirrors on your skin. These microscopic particles sit on the surface and physically block, scatter, and reflect UV rays away from your skin.

Think of it like holding up a shield. When UV radiation hits these mineral particles, it bounces off in different directions rather than penetrating your skin. Zinc oxide provides broad-spectrum protection against both UVA and UVB rays, while titanium dioxide primarily protects against UVB rays.

The “white cast” that older mineral sunscreens were notorious for occurs when these mineral particles are too large, making them visible to the naked eye. Modern formulations use nano-sized particles that maintain protection while becoming virtually invisible on the skin.

Chemical Sunscreens

Chemical sunscreens work through a completely different process. Rather than deflecting UV rays, they absorb them. They contain organic compounds like avobenzone, octinoxate, octisalate, and oxybenzone with a specific molecular structure that allows them to absorb UV photons. When a UV ray hits a chemical sunscreen molecule, it causes the molecule to reach an excited state. The molecule then releases this energy as heat, effectively neutralizing the UV radiation before it can damage your skin cells.⁹

Different chemical ingredients target distinct types of UV rays. For example, avobenzone excels at UVA protection, while octinoxate primarily handles UVB rays. This is why many chemical sunscreens combine multiple active ingredients to achieve broad-spectrum protection.

Other Sunscreen Qualities

Beyond the basic formulation, there are other sunscreen characteristics to consider when selecting one:

• Broad-spectrum protection is non-negotiable. This means the sunscreen protects against both UVA and UVB rays. 
• SPF 30 or higher provides adequate protection for most people. However, if you have fair skin, a history of skin cancer, or spend significant time outdoors, consider SPF 50 or higher.
• Water resistance is important if you will be swimming or sweating. Remember that no sunscreen is completely waterproof, so reapplication is still necessary.
• Formulation matters for compliance. If you dislike the feel of traditional sunscreens, try mineral formulations with zinc oxide or titanium dioxide, or newer chemical sunscreens with improved textures.

The Truth About SPF Numbers

One of the most common questions we hear at our Greenville dermatology practice is about SPF ratings. SPF stands for “sun protection factor,” and it measures how long you can stay in the sun without burning compared to not wearing any sunscreen.

The relationship between SPF numbers and protection is more nuanced than most people realize. They correspond to the level of protection related to the percentage of the sun’s UVB rays: 

• SPF 15: Blocks approximately 93% of UVB rays
• SPF 30 blocks about 97% of UVB rays
• SPF 50 blocks roughly 98% of UVB rays

It is worth noting that the 4 percent difference in the sunlight it blocks can be profound. Even the 1 percent difference between SPF 50 and SPF 30 can be significant, especially for people with fair skin or those who spend a lot of time in the sun. 

The key takeaway is that any sunscreen with SPF 30 or higher provides excellent protection when applied correctly. However, higher SPF numbers can offer a margin of error for real-world application, where most people do not apply enough product to achieve the labeled protection.

Debunking Common Sunscreen Myths

Here are some of the most common misconceptions related to sunscreen. 

Myth 1: “A Higher SPF Rating Translates to Longer-Lasting Protection”

Many patients think, for instance, that an SPF 50 sunscreen lasts almost twice as long or is twice as effective as an SPF 30 product. As mentioned, these numbers relate to the percentage of UVB rays they each block. It is true that an SPF 50 blocks more rays, but it is not twice as effective.

The numbers also have to bearing on longevity. An SPF 70 or SPF 100 still needs to be reapplied as frequently as an SPF 15. 

Myth 2: “I Don’t Need Sunscreen on Cloudy Days”

This is one of the most dangerous misconceptions about sun protection. More than 90 percent of UV rays can penetrate clouds, meaning you are still at risk for sun damage even when it is overcast outside.¹⁰

UV radiation is present year-round, regardless of weather conditions. This is why dermatologists recommend wearing sunscreen every day, whether you’re spending time outdoors or just commuting to work.

Myth 3: “Darker Skin Doesn’t Need Sunscreen”

While it is true that melanin provides some natural protection against UV radiation, people with darker skin tones are still susceptible to sun damage and skin cancer. The benefits of sunscreen extend to everyone, regardless of skin color. In fact, when skin cancers develop in people with darker skin, they’re often diagnosed at later stages, making them more dangerous.

Myth 4: “Sunscreen Prevents Vitamin D Production”

Some people avoid wearing sunscreen because they are concerned about getting enough vitamin D. While sunscreen can reduce vitamin D synthesis, most people get adequate vitamin D through brief sun exposures during daily activities, even while wearing sunscreen. The health risks associated with excessive sun exposure far outweigh the potential benefits of unprotected UV exposure for vitamin D production.

Myth 5: “Expensive Sunscreens Work Better”

Price does not always correlate with effectiveness. Many drugstore sunscreens provide excellent protection at a fraction of the cost of luxury brands. The most important factors to look for are that it offers broad-spectrum protection (meaning it blocks both UVA and UVB rays) and that it has an appropriate SPF rating. Beyond that, the main thing is proper application. 

To put a fine point on it: as a Greenville dermatologist, I often recommend affordable, effective options that patients are more likely to use consistently. Higher prices could make people too conservative in their application of the sunscreen or cause them not to buy it in the first place. Once again, the best sunscreen is the one you are most likely to put on and reapply regularly. 

Myth 6: “Chemical Sunscreens Are Dangerous”

This is debatable. Chemicals in sunscreen can indeed be absorbed into the bloodstream (though that alone does not necessarily mean they are bad for you). There are ongoing studies looking at the impacts they can have, including with long-term use.¹¹

The general consensus though—among scientists at the FDA and elsewhere, and the vast majority of dermatologists—is that the protections provided by the use of sunscreen far outweigh any dangers they might pose. However, if you have concerns about sensitivity or safety related to chemical sunscreens, there are myriad mineral ones to choose from. 

Daily Sunscreen Use: More Important Than You Think

The question “Should I wear sunscreen everyday?” comes up frequently in our Greenville SC dermatology practice, and the answer is a resounding “yes!” Daily sunscreen application is one of the most important steps you can take to protect your skin health.

UV radiation is present whenever you are outdoors, even during brief activities like walking to your car or sitting near a window. These seemingly minor sun exposures accumulate over time, contributing to skin damage and increasing cancer risk. By making sunscreen part of your daily routine, you are providing consistent protection against these cumulative effects.

For optimal protection, apply sunscreen to all exposed skin 15-30 minutes before going outside. Also, do not forget often-missed areas like your ears, neck, hands, and feet. Reapplication every two hours is essential, especially if you are swimming, sweating, or spending extended time outdoors.

Understanding the “Full Spectrum” of Sunscreen Benefits

The sunscreen benefits extend far beyond basic sun protection. Regular use can help maintain an even skin tone, prevent the development of dark spots and hyperpigmentation, and preserve your skin’s natural texture and elasticity.

Sunscreen also plays a crucial role in managing existing skin conditions. Patients with melasma, rosacea, or post-inflammatory hyperpigmentation often see improvement in their conditions with consistent sun protection. For those undergoing certain dermatological treatments, sunscreen is essential for preventing complications and ensuring optimal results.

While this information provides a solid foundation for understanding sunscreen, individual skin needs vary significantly. Factors like skin type, personal history, lifestyle, and existing skin conditions all influence the best sun protection strategy for you.

Learn More About Sunscreen Use and Benefits

Protecting your skin from sun damage is one of the most important investments you can make in your long-term health and appearance. By understanding the facts about sunscreen and debunking common myths, you will be better equipped to make informed decisions about sun protection.

Remember, the best sunscreen is the one you will apply and reapply consistently. Whether you prefer a lightweight daily moisturizer with SPF or a sport-specific formula for outdoor activities, the key is making sun protection a non-negotiable part of your routine.

Your skin will thank you for the protection you provide today, and you will be taking a significant step toward reducing your risk of skin cancer while maintaining healthy, youthful-looking skin for years to come. Reach out to us today to learn more about protecting your skin or to schedule an appointment for any concerns you may have.

---

References

1. Angela Giaquinto, Tyler Kratzer, Rebecca Siegel, and Ahmedin Jemal, Cancer Facts & Figures 2025, Surveillance and Health Equity Science Department, American Cancer Society, 2025, https://www.cancer.org/content/dam/cancer-org/research/cancer-facts-and-statistics/annual-cancer-facts-and-figures/2025/2025-cancer-facts-and-figures-acs.pdf.
2. Rachel Grumman Bender, “More than 30% of U.S. adults never use sunscreen, new Yahoo News/YouGov poll finds,” Yahoo.com, May 2024, https://www.yahoo.com/lifestyle/more-than-30-of-us-adults-never-use-sunscreen-new-yahoo-newsyougov-poll-finds-140517676.html.
   
3. Heather Alexander, “What’s the difference between UVA and UVB rays?” MD Anderson Cancer Center, The University of Texas, June 2019, https://www.mdanderson.org/publications/focused-on-health/what-s-the-difference-between-uva-and-uvb-rays-.h15-1592991.html. 
4. Supriya Subramanian, Ph.D., “The Mechanism of DNA Damage by UV Radiation,” News-Medical.net, https://www.news-medical.net/life-sciences/The-Mechanism-of-DNA-Damage-by-UV-Radiation.aspx.
5. Kozo Nakai and Daisuke Tsuruta, “What Are Reactive Oxygen Species, Free Radicals, and Oxidative Stress in Skin Diseases?” International Journal of Molecular Sciences, October 2021, https://pmc.ncbi.nlm.nih.gov/articles/PMC8509443/. 
6. Chao Feng, Xianglong Chen, Xiuqing Yin, Yanfei Jiang, and Chunyue Zhao, “Matrix Metalloproteinases on Skin Photoaging,” Journal of Cosmetic Dermatology, September 2024, https://pubmed.ncbi.nlm.nih.gov/39230065/.
7. Caroline G. Watts, Martin Drummond, Chris Goumas, Helen Schmid, et al., “Sunscreen Use and Melanoma Risk Among Young Australian Adults,” JAMA Network, July 2018, https://pmc.ncbi.nlm.nih.gov/articles/PMC6143037/.
8. Samantha L Schneider and Henry W Lim, “A review of inorganic UV filters zinc oxide and titanium dioxide,” Photodermatology, Photoimmunology, and Photomedicine, November 2018, https://pubmed.ncbi.nlm.nih.gov/30444533/.
9. “Review of Fate, Exposure, and Effects of Sunscreens in Aquatic Environments and Implications for Sunscreen Usage and Human Health,” National Academy of Sciences, Engineering, and Medicine, National Academies Press, August 2022, https://www.ncbi.nlm.nih.gov/books/NBK587270/. 
10. Sasha Santhakumar, “Is it possible to get sunburn on a cloudy day?” Medical News Today, March 2023, https://www.medicalnewstoday.com/articles/can-you-get-sunburn-on-a-cloudy-day. 
11. Joanna A. Ruszkiewicz, Adi Pinkas, Beatriz Ferrer, et al., “Neurotoxic effect of active ingredients in sunscreen products, a contemporary review,” Toxicology Reports, May 2017, https://pmc.ncbi.nlm.nih.gov/articles/PMC5615097/.