Sunscreen Ingredients: What Actually Works and What to Avoid

When you pick up a bottle of sunscreen, a topical product designed to protect skin from harmful ultraviolet radiation. Also known as sunblock, it's one of the few daily health habits backed by decades of clinical evidence. But not all sunscreens are the same—what’s on the label can make a huge difference in how well it works and whether it’s safe for you and the environment.

The two main types of sunscreen ingredients are zinc oxide, a mineral filter that sits on top of the skin and physically blocks UV rays and titanium dioxide, another mineral that works similarly but offers slightly less broad-spectrum protection. These are the gold standard for sensitive skin, kids, and anyone worried about chemical absorption. On the other side, oxybenzone, a common chemical filter that absorbs UV light and converts it to heat, has raised concerns about hormone disruption and coral reef damage. The FDA has flagged it as potentially absorbed into the bloodstream at levels higher than safety thresholds, yet it’s still in many popular brands.

Here’s the simple truth: if you’re looking for reliable protection without unknown side effects, mineral sunscreens with zinc oxide or titanium dioxide are your best bet. They start working immediately, don’t break down as fast in sunlight, and are less likely to cause irritation. Avoid products with oxybenzone, octinoxate, or homosalate if you’re pregnant, have acne-prone skin, or care about ocean health. Don’t be fooled by "reef-safe" labels—those aren’t regulated. Look for the actual ingredients list instead.

SPF 30 is enough for daily use. Higher numbers like SPF 100 give a false sense of security and don’t offer much more protection. What matters more is how much you apply and how often you reapply—every two hours, or after swimming or sweating. And yes, you need it even on cloudy days. UV rays penetrate clouds, and UVA rays that age your skin are present all day, every day.

The posts below cover real-world insights on sunscreen ingredients—from how they interact with other skincare products, to why some formulas fail in real use, to what dermatologists tell their own families. You’ll find clear breakdowns of what’s safe, what’s overhyped, and what’s quietly dangerous. No marketing fluff. Just facts you can use to pick the right bottle the next time you shop.