The Dark Side of Lightweight Sunscreens

Everyone's loving light sunscreens these days. People who use sunscreen every day are all about sunscreens that work well, go on smooth, and you can't even tell they're there. Now, there's a bunch of brands selling these "ultra light" versions, and everyone who's into skincare is trying to find the lightest one out there. But here's the thing, though: these lighter sunscreens might not protect you from the sun as much as you think they would.

You need an even layer

To provide effective protection, sunscreen needs to create an even layer on the surface of your skin. This is crucial because our skin isn't flat - it has its own landscape of hills and valleys. A thin layer of sunscreen over this uneven surface could result in patchy coverage. The sunscreen might fill or cover the "valleys" of your skin but may not adequately cover the "peaks", similar to painting a rough wall with a small amount of paint on your brush.

The trap of thin application

With a lighter texture, it's easier - and often more tempting - to apply a thinner layer of sunscreen. It's crucial to remember, though, that SPF testing uses a specific amount of sunscreen: 2 mg for each square centimeter of skin. To visualize how much that is for an average face, imagine an amount of sunscreen slightly larger than a US quarter coin. This is a substantial amount to spread over your face - you may even need two layers if the product is especially thin. If you apply less than this, you won't get the protection level stated on the product label.

Risks of under-application

In fact, if a product is marketed with an SPF 50 rating but is applied in an amount less than 2 mg per square cm, it may not even reach the minimum SPF rating of 15. This is due to the failure to adequately cover those "skin hills".

If you don't feel any sunscreen residue after applying it, this might signal that you haven't applied enough, and a proper protective film hasn't been formed. As a result, most of your skin may not be protected. This can be particularly risky because you might believe you're safe to spend time in the sun just because you've applied some sunscreen.

Bottom line

The key takeaway? Don't let the allure of lightweight sunscreens compromise your skin's protection. Apply enough, and apply it evenly. Consider to going for a thicker texture when going to a beach or if you plan to spend the whole day outdoors in sunlight. 

WIMJ Search allows you to select skincare products based on what's inside. Filter products by actives included, and exclude ingredients you don't want. Check the concentration of ingredients and potential irritants.

• Application of sunscreen − theory and reality https://onlinelibrary.wiley.com/doi/full/10.1111/phpp.12099
• Skin Surface Topography and Texture Analysis of Sun-Exposed Body Sites in View of Sunscreen Application https://karger.com/spp/article-abstract/29/6/291/295887/Skin-Surface-Topography-and-Texture-Analysis-of?redirectedFrom=fulltext 

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