Why You Can't Completely Trust UV-Testing TikTok Videos Telling You What Sunscreen To Buy

TikTok has seemingly become a main source of news and advice for many people. From pop culture and world news to trend forecasting and health and wellness hacks, the popular app truly covers all bases. Look it up and there it is, ready to be implemented into your feed by the invisible hand of the algorithm. This includes skincare advice, which is abundant, including tips for ensuring you buy the right sunscreen for your skin type. And, if you're on the side of "SkinTok" (skincare TikTok) that we're on, then you've definitely come across a certain genre of video claiming to be able to tell the efficiency and potency of a sunscreen with the help of a UV light machine. But is this method legit? That's up for debate.


What these TikTokers are doing is applying the correct amount of sunscreen from each brand they test and filming their faces with a device that measures how much UV light is penetrating the skin. The problem? It isn't always accurate.

What is SPF, and does it protect against all UV rays?

SPF (sun protection factor) signifies the level of protection of any given sunscreen against the sun or, in other words, how much UV radiation is necessary to burn or damage the skin. The higher the SPF, the more protected the skin.


UV rays are categorized into two different types, and not all sunscreens protect properly against both. UVB rays, to put it simply, are responsible for burning the skin, while UVA rays cause aging of the skin. Yes, sadly, unprotected exposure to the sun can lead to premature signs of aging, such as fine lines and hyperpigmentation. 

You can rest assured that all sunscreens are regulated to protect against UVB rays, but here's how to tell if they also protect against those pesky UVAs. Always keep the sunscreen container and see whether it specifies UVA somewhere on the label. If so, you're set. If the bottle has a PA followed by a number of pluses (maximum efficiency being PA ++++), even better.


Why is SPF so important?

Sun rays have been proven not only capable of causing burns and other skin conditions, which include skin cancer, but also of causing the skin to age at faster rates. Daily use of sunscreen significantly diminishes your likelihood of developing melanoma and other skin conditions caused by unprotected sun exposure, and it also protects against photosensitivity from topical products or medications. You'd be surprised to learn how much of your skincare routine is actually causing your skin to be more sensitive to the sun (think retinol and vitamin C). Plus, you are never too young to protect your skin from the aging effects of sunshine.


So, how do you choose the best sunscreen for your skin? Most dermatologists recommend SPF 30 and up for the face and daily application (reapplying every two hours) for consistent sun protection, especially if you plan on spending any time outdoors. Keep this in mind: Rain or shine, sunscreen is a must.

How to tell the efficiency of SPF

Sadly, TikTok cannot be trusted with testing the efficiency of sunscreen. Official lab tests, on the other hand, can be trusted almost blindly. To be able to label the potency of their sunscreen, brands need to independently or externally test a product's SPF levels in a lab. These tests are conducted by using 1/3 of a teaspoon of sunscreen, which is the amount needed to properly protect a person's face from the sun.


If a product is able to block 98% of UV rays, its label should be SPF 15. If it blocks 97% of rays, it's labeled as SPF 30, while 98% is labeled as SPF 50. This is officially regulated by the FDA for all sunscreens sold within the U.S.

All in all, the only way to be sure of a sunscreen's efficiency is to look at its SPF label. Thanks, scientists.