Twenty years ago, buying sunscreen was refreshingly simple. You picked an SPF, threw it in your beach bag and got on with your holiday. Today, sunscreen has become one of the most debated products in our skincare routines.
Open Instagram or TikTok and you'll find endless opinions. One creator insists chemical sunscreens are harmful. Another says mineral sunscreens are impossible to blend. Some claim sunscreen blocks vitamin D. Others argue we should skip SPF altogether and rely on "building a base tan". Add in conversations around endocrine disruptors, reef safety, nanoparticles and ingredient lists, and it's no surprise consumers are left wondering who to believe.
The reality is that we're more informed than ever, yet choosing a sunscreen has never felt more confusing.
Why has the SPF debate become so loud?
The growing conversation around sunscreen is part of a much bigger shift. Consumers today are far more ingredient-conscious than they were a decade ago. Apps like Yuka have encouraged people to scan products before buying them. We're reading ingredient lists, asking questions and taking a more active interest in what we put on our bodies. That's undoubtedly a positive thing.
The problem is that scientific research rarely translates neatly into a fifteen-second video. Nuance often disappears, and the most alarming headline spreads the fastest. What I've learned is that the truth is usually far less dramatic than social media would have us believe.
Mineral vs chemical: what's the actual difference?
At their core, both mineral and chemical sunscreens exist for the same reason: to protect your skin from ultraviolet (UV) radiation and reduce the risk of sun damage and skin cancer. The difference lies in the UV filters they use and how those filters work.
Mineral sunscreens use zinc oxide or titanium dioxide, naturally occurring mineral UV filters that sit on the surface of the skin, forming a protective layer. They help protect the skin by reflecting, scattering and absorbing UV rays before they can cause damage. Chemical sunscreens use synthetic UV filters that absorb UV radiation and convert it into heat before releasing it from the skin. They're often favoured for their lightweight, invisible finish.
For many people, including many a Grounded reader, the appeal of mineral sunscreen goes beyond texture. Zinc oxide and titanium dioxide have long been recognised for being gentle on the skin, making them a popular choice for those with sensitive or reactive skin, as well as anyone who prefers a simpler, more considered approach to skincare.
Some of the most commonly used chemical UV filters, including oxybenzone, octinoxate, octocrylene and homosalate, continue to be studied for their absorption through the skin, potential effects on the endocrine system and environmental impact. While the evidence is still being assessed, many people choose mineral UV filters because they offer broad-spectrum protection without raising the same questions.
Historically, mineral formulas have been associated with thicker textures and a visible white cast, but advances in formulation are making them increasingly elegant, helping to close the gap in texture and appearance.
When should you wear sunscreen?
We've talked about choosing the right sunscreen, but knowing when to use it is just as important. Rather than choosing between sunlight and sunscreen, it's about understanding when your skin needs protection and when it's safe to enjoy the sun.
Sensible sunlight exposure plays an important role in our overall wellbeing. Morning or late afternoon sunlight can support circadian rhythm, mood and vitamin D production while reducing the likelihood of intense UV exposure. A UV Index of 3 or above (your phone's weather app should show you hourly levels) is the point at which it's recommended to seek shade, cover up or apply sunscreen.
One of the biggest misconceptions in the SPF debate, however, is that wearing sunscreen leads to vitamin D deficiency. While sunscreen reduces the UVB rays needed to make vitamin D, it doesn't block them completely. No sunscreen blocks 100% of UVB radiation, and current research suggests that everyday sunscreen use has little impact on vitamin D levels.
The bottom line
The internet will probably continue debating sunscreen for years to come. But perhaps that's not a bad thing. Consumers asking more questions have encouraged the industry to innovate, improve formulations and be more transparent than ever.
Whether you choose a mineral or chemical sunscreen is ultimately a personal decision. The most important thing is finding a product that suits your skin, aligns with your priorities and is one you'll enjoy wearing. Whichever formula you choose, protecting your skin from UV damage is what matters most.
