0
0
PARIS, FRANCE – A recent study conducted by researchers at the French National Centre for Scientific Research (CNRS) has raised concerns about the common practice of combining sunscreen and insect repellent. The research, published in the journal Parasites & Vectors, indicates that the combined use of these products may significantly reduce the level of ultraviolet (UV) protection offered by sunscreen.
With the increasing prevalence of tiger mosquitoes in numerous countries, many individuals routinely apply both sunscreen and insect repellent during outdoor activities. However, until now, the effects of combining these products had not been thoroughly investigated.
The CNRS study employed a novel approach, utilizing ex vivo human skin biopsies to simulate real-world conditions. These samples were exposed to both artificial and natural UV radiation after the application of sunscreen and a popular insect repellent. Researchers then used a cutting-edge computer tool, powered by deep-learning artificial intelligence, to analyze thin slices of the skin samples, allowing for a detailed assessment of the skin cells’ stress response to the radiation.
The analysis revealed a notable decrease in UV protection when sunscreen and insect repellent were applied in combination. Interestingly, the results for products marketed as “mixed” sunscreen-repellents were less conclusive, highlighting the need for further research in this area.
“This is the first study to examine the impact of mixing sunscreen and insect repellent on UV protection using human skin biopsies,” stated a researcher involved in the study. “Our findings suggest that combining these products may compromise the effectiveness of sunscreen, potentially increasing the risk of sun damage.”
The researchers emphasized the importance of this new analytical method, which combines the use of skin biopsies with artificial intelligence, for evaluating the effects of other product mixtures, including cosmetics, on human health. This approach offers a more reliable alternative to traditional in vitro cell culture tests.
“Many product combinations used daily have never been rigorously tested,” explained a spokesperson for CNRS. “This new method allows us to examine their effects on human skin with greater accuracy, potentially leading to improved safety guidelines.”
The study, titled “Computational histology reveals that concomitant application of insect repellent with sunscreen impairs UV protection in an ex vivo human skin model,” was published in Parasites & Vectors (2025). The DOI is: 10.1186/s13071-025-06712-3.
Disclaimer: This news article is based on the provided research information. Readers should consult with a dermatologist or healthcare professional for personalized advice regarding sun protection and insect repellent use. Further research is needed to confirm and expand upon these initial findings. The results presented here may not apply to all sunscreen and insect repellent formulations.
