Despite decades of educational efforts, there is growing public skepticism over sunscreen’s safety and efficacy. Researchers from Chicago sought to synthesize the current scientific understanding of sunscreen in order to help dermatology clinicians address concerns. The findings are published in the February Journal of Drugs in Dermatology.
I interviewed author Natalia Chalupczak, medical student at Rosalind Franklin University’s Chicago Medical School, for her thoughts on how dermatology clinicians can best apply these findings when counseling patients on sun protection.
What led you to want to take a deep dive into sunscreen?
We were discussing how sometimes on social media dermatologists can be disparaged by chemists and formulators for not really understanding the science of sunscreens. That prompted us to do an up-to-date deep dive into the science and chemistry for dermatologists to push back against misinformation. We wanted to provide a comprehensive, evidence-based review that would clarify mechanisms, efficacy, and safety, helping dermatology professionals better counsel their patients.
In your study, you sought to dispel popular myths about sunscreen. Was there one myth that you particularly wanted to debunk?
The most pervasive myth we aimed to debunk is that “mineral sunscreens simply reflect, while chemical sunscreens absorb.” The reality is more complex. Mineral sunscreens (zinc oxide and titanium dioxide) don’t just reflect UV rays; they also absorb and scatter them. Similarly, chemical sunscreens don’t just absorb UV light but can have secondary photoprotective mechanisms as well. This oversimplification has contributed to confusion among both patients and clinicians, and we wanted to set the record straight.
How did you conduct your research?
We conducted an extensive literature review of peer-reviewed studies examining the mechanisms of action, efficacy, safety, and regulatory considerations surrounding sunscreen ingredients. We synthesized findings from clinical trials, toxicology studies, and FDA regulatory updates to provide a balanced and comprehensive perspective. Our goal was to critically assess the scientific evidence and present it in a way that dermatology professionals could apply in both clinical practice and patient education.
What is the most important takeaway from your investigation into sunscreen’s mechanisms of action? How should your findings impact patient education?
The key takeaway is that both chemical and mineral sunscreens offer effective photoprotection, but their mechanisms are more nuanced than commonly believed. Patients should understand that zinc oxide and titanium dioxide don’t merely reflect UV radiation—they also absorb and scatter it, providing broad-spectrum protection. Educating patients on these differences can help them make informed choices rather than being swayed by marketing claims or misinformation.
What’s helpful for dermatology clinicians to know about sunscreen efficacy?
Sunscreen efficacy is primarily measured through SPF (UVB protection) and persistent pigment darkening (PPD) for UVA protection. However, adherence remains a major challenge—many patients don’t apply enough sunscreen or reapply as often as they should. Dermatology clinicians should emphasize correct application techniques, including using a sufficient amount and reapplying every two hours, especially when outdoors. Broad-spectrum protection and water resistance should also be key considerations when recommending sunscreens.
What did your research reveal about systemic absorption of chemical sunscreens?
Recent studies have shown that certain chemical sunscreen ingredients, such as oxybenzone and octinoxate, can be detected in plasma at higher levels than previously expected. While this raised concerns, no conclusive evidence has demonstrated harm in humans at these levels. The European Commission has placed stricter limits on oxybenzone, and some regions have banned it. However, based on the current data, dermatologists can reassure patients that the benefits of using sunscreen to prevent skin cancer and photoaging far outweigh any theoretical risks.
Your research also found potential concerns with some sunscreens that use physical blockers. What were your findings?
While mineral sunscreens are often recommended for their safety profile, our research found some potential concerns with their nanoparticle formulations. Micronized zinc oxide and titanium dioxide, which are used to create more cosmetically elegant formulations, may have altered refractive properties that could impact UVA protection. Additionally, in certain environmental conditions, such as chlorinated water, the coatings used to prevent the generation of reactive oxygen species may degrade, raising concerns about potential cellular damage. More research is needed to fully understand these implications.
What are your recommendations for dermatology clinicians in counseling their patients about sunscreen use?
Clinicians should continue to emphasize that sunscreen is a crucial tool in preventing skin cancer and photoaging. When counseling patients, it’s important to tailor recommendations to individual needs—whether that means suggesting mineral sunscreens for sensitive skin or water-resistant formulations for outdoor activities. Additionally, dermatologists should address common myths directly, reassuring patients that sunscreen safety concerns should not deter them from using photoprotection. Reminding patients that sunscreen is just one part of a broader sun protection strategy, which includes protective clothing and seeking shade, is also very important.
Are there any other key takeaways from your study that dermatology clinicians should know?
Dermatologists and clinicians should be aware of evolving regulatory policies and emerging research on sunscreen safety. The FDA has proposed updates to its sunscreen regulations, indicating the need for more safety data on certain chemical UV filters. Additionally, environmental concerns—especially related to coral reef safety—have led to bans on specific sunscreen ingredients in some regions. While these topics are still being studied, dermatologists can confidently reassure patients that sunscreens remain a safe and essential component of sun protection.
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