Not Effective as a Sunscreen Monitor
I had high hopes for these UV stickers as a way to test sunscreen effectiveness, but they just don’t work as advertised. Both the sunscreen-coated and uncoated stickers turned purple immediately when I stepped outside, and they both went clear again when I came back in. They cycled back and forth dozens of times throughout the day. With my mineral sunscreen (zinc oxide-based), the sunscreen-coated sticker didn’t really look any different than the unprotected one. My theory: the slick plastic patch can’t actually absorb the zinc, so it just rubs off. On top of that, the slick plastic surface of the stickers doesn’t mimic skin at all—no sweat, no oil, no absorption—so comparisons aren’t realistic anyway. It’s possible they work better with a chemical sunscreen, but there is no mention of this on the packaging or item description. It would also seem odd to highlight children on the packaging and instructions (“Apply the patch to the child’s skin”) if they do not work with mineral sunscreen, when the vast majority of kid’s sunscreens are mineral based. That said, they are highly sensitive to UV light, which makes them excellent for testing things like whether your window tint blocks UV or if a lamp actually emits UV rays. If they were advertised simply as UV detection stickers, I’d give them 5 stars. As sunscreen monitors? They miss the mark. Read more
