EnergeticCrabβJune 26, 2024
I bought these to test sunscreens. I accumulated many sunscreens that over the years are past their expiration date but wanted to see if they were still effective. The stickers are clear inside and when you bring them outside into sunlight, they turn purple. I put the stickers on my arm inside, applied the sunscreen, and then walked outside. The stickers turned purple. Thus proving the sunscreens were no longer effective at blocking UV. These stickers would probably be great for everyday wear, as a reminder to reapply! I liked the shapes they came in, too. They arrived with no instructions or labels. The sticker is also stayed on after washing the sunscreen off my arm, so they are probably good at resisting sweat for a number of hours. Read more
Hannah QueenβJuly 13, 2025
When I first used them, I put them on my children's arms without sunscreen. Then applied sunscreen over the stickers before going outside. As soon as they got in the sun, the sticker turned purple and never changed back to clear. I re-read the directions on the Amazon page (because the package did not have directions) and tried it again on my own hand. Put the sticker on, then sunscreen, then sat in the sun with the sticker on my hand exposed. Nothing. Stayed purple the whole time. Maybe I got a defective batch, but they were not helpful. Read more
RHurleyβJune 28, 2024
These little dudes were sold to us like they'd be like sunscreen timers. In the Florida sun, they turned purple immediately. Literally 5 minutes in the sun. Not sure really if that was the intent so I'm not making it 1 star. You get 3 stars. And that's kind. Read more
Itβll destroy furnitureβJune 27, 2024
Wearing SPF 50 (albeit in June in Arizona) they are triggering even immediately after applying sunscreen. Not as dark as before application, but it will make it a bit trickier to know when to reapply. Otherwise they seem pretty good. Read more
Diane ThomasβOctober 22, 2025
I keep these in my beach bag and they work great. Will buy them again. Read more
mjβJuly 31, 2025
Maybe you can use these to test the effectiveness of upf clothing, but sunscreen has no effect on these. Iβve tried multiple brands and types, waited after applying and still no effect. Just turns purple as soon as exposed to the sun. Read more
Kristen AtkinsβMay 22, 2025
They donβt stick very well Read more
Courtney G. MillesonβSeptember 15, 2024
We took these for a WDW trip for my fair-skinned hubby. As a ginger, the Florida sun is not his friend. He said, "They were a great reminder of just how often I needed to put on sunscreen. I don't know if I need them again, but I'll probably use them just as a reminder." Needless to say, they're on our family's Disney shopping list. It's just so easy to get caught up in the fun, that you forget to take care of yourself, too. Read more