Explainer / What are UV test stickers – and how do you use them? These adhesive strips change colour when you need to reapply sunscreen, but dermatologists advise incorporating other sun protection practices too

Jul 26 , 2023

Young woman with sun shape on the shoulder holding sun cream bottle on the beach

It’s summertime! Are you taking precautions to look after your skin while you’re out and about? Consider trying UV test stickers by beauty brands such as Naomi Osaka’s Kinlò

Dermatologists say it’s crucial to understand their limitations and incorporate other sun protection practices, like choosing a broad spectrum sunscreen with SPF of 30 or higher and wearing hats

Summer is in full swing and as we revel in the sunny outdoors, it’s essential to protect our skin from harmful UV rays.

Oscar-winning actress Michelle Yeoh’s youthful beauty regime suggests slathering on sunscreen religiously while Everyday Humans’ Charlotte Chen also emphasises the importance of suncare. It’s a no brainer that the key guardian in this battle is sunscreen, but do we truly know how much we need to apply for adequate protection?

Luckily, innovative tools like UV test stickers claim to hold the answer to this age-old mystery.

How much sunscreen do you need?

UV detection stickers are useful for understanding how much sunscreen is needed for coverage. Photo: Spot My UV

To start, it’s essential to grasp the recommended amount of sunscreen for proper coverage.

Dermatologists advise applying at least one ounce, equivalent to a shot glass, of sunscreen to cover the entire body. When it comes to the face, experts suggest using the “two fingers” technique, dispensing enough sunscreen to cover the length of two adult fingers.

Follow dermatologists’ advice and apply two fingers’ worth of sunscreen protection to your face. Photo: AXIS-Y

If teaspoons are easier to visualise, think of it this way: you need half a teaspoon of sunscreen for your face and neck, one teaspoon to cover both your arms, one teaspoon for the front of your torso, and another teaspoon for your back and shoulders. Finally, you’ll need two teaspoons to spread over both your legs.

Emily Trampetti, master licensed esthetician and founder of Skin Property Virtual Esthetics, highlights the ongoing debate surrounding sunscreen safety, with customers being inundated with a mix of new and, at times, misleading scientific information. Trampetti emphasises, “There are also increasingly popular, fearmongering opinions that sunscreens are ‘harmful’ or ‘unsafe’.”

Apply sunscreen when you spend time outside in order to protect your skin from harmful UV rays. Photo: Shutterstock

But from a scientific perspective, it’s crucial to understand that UV rays from the sun are the only proven carcinogens. “That is far more than we can say of any sunscreen ingredient,” Trampetti explains. “And most of the diligent scientific community agrees that the best sunscreen you can apply to yourself or your children is the one you have access to.”

Additionally, reapplication remains a critical aspect of sun protection.