Adding a special compound called β-cyclodextrin to sunscreen might help keep more of the chemical filters from soaking into your skin—but that doesn’t mean it makes the sunscreen safer for your body or less likely to cause allergies in people.

When you mix three common sunscreen chemicals with a special ring-shaped molecule called β-cyclodextrin, they don’t soak into the skin as much—up to 15 times less—so they might stay on top of your skin where they’re supposed to work, instead of getting absorbed inside your body.

When these common sunscreen chemicals are wrapped in a special sugar-like molecule called β-cyclodextrin, they take over 2.5 hours to start getting through the skin of rat skin in a lab test—meaning they’re slower to be absorbed, which might make them safer.

When sunscreen chemicals like avobenzone are trapped inside a special ring-shaped molecule called β-cyclodextrin, they don’t soak into the skin as much as when they’re just mixed in — and this works better in a creamy lotion base using rat skin in a lab test.

Scientists found that a special ring-shaped molecule called β-cyclodextrin can trap three common sunscreen chemicals inside it, and when it does, those chemicals behave differently when they touch simulated skin in a lab dish.

When you put on sunscreen with chemicals like oxybenzone or avobenzone, your body absorbs more of those chemicals into your bloodstream than the FDA thinks is safe — even if you just use it normally on your skin.