[UPDATED JULY 12 2023] 7 Things You Did Not Know About Sunscreens

When it comes to skincare, the number one advice we always hear is “wearing sunscreen.” Why? Because ultraviolet (UV) radiation rays from the sun can cause significant damage to our skin, sometimes beyond a quick and easy repair. Because sunscreen is such an important (and indispensable) step in taking care of your skin, we wanted to make a simple and easy-to-understand guide to all things SPF so you can take it as seriously as we do!

What is UVA and UVB?

There are two types of UV rays: UVA and UVB. UVA rays can prematurely age your skin, causing wrinkling and age spots. UVB rays can burn your skin. Of course, the immediate thought always goes to hyperpigmentation and burning of the skin on our face and body, but too much exposure to UVA or UVB rays can cause skin cancer, which is ultimately what we are trying to avoid as well as make sure we are not prematurely aging ourselves. You should be looking for a broad-spectrum (meaning, protection from both UVA and UVB) with an SPF of 30+.

What is SPF and how does it work?

SPF is an acronym for “Sun Protection Factor,” or in other words, how well it protects your skin from UVB rays (the ones that burn your skin). There is a popular rumor that the SPF number refers to the time you can spend exposed to the sun, as in, the higher the number, the longer you can stay in the sunlight. But that is just not true. The SPF number actually correlates to the amount of solar exposure you can have. So, for example, you may be able to be out for an hour with 30+SPF in the sunlight around 9:00am, but for only 15 minutes around 12:00 noon, when the energy and intensity of the sun is much brighter. Because clouds absorb solar energy, solar intensity is generally greater on clear days than cloudy days. Take note that also, even if you are indoors, there will be solar rays that can still affect your skin. Same goes for when you are on an airplane!

For all those of us located near the equator and have felt the heat, it is only logical that solar intensity is also related to geographic location, with greater intensity occurring at lower latitudes.


What’s better? SPF 30+ or 50+?

Scientifically, SPF that is more than 30+ provides a bit more protection than its 30+ counterpart. SPF 30+ provides about 93%-97% protection against UVB rays. However, SPF 50+ provides 98%-99% protection. It may not seem like a huge difference, but in the world of aesthetics, those extra 2% can mean real results. So is SPF 30+ a good rule of thumb? Yes. Do we prefer 50+? Absolutely.

iLomys Renew Derm No.4 Suncream SPF50+ PA+++

What about protection from UVA rays?

While most sunscreens are not rated for UVA protection, more recently many Korean products have begin indicating UVA protection through a Protection for UVA (PA) which measures Persistent Pigment Darkening (PPD). You will usually see the different grades of protection indicated with a “+” sign. You can check out our handy guide for the UVA preventative effect in the infographic below:


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A post shared by Eunogo Shop (@eunogoshop)


What is the difference between chemical and mineral Sunscreen?

Great question! While both chemical and mineral (physical) ingredients can help protect your skin from UVA and UVB rays, there are differences in how they work. A chemical SPF will have active ingredients that create a non-physical barrier between you and the sun. These ingredients, such as Octocrylene, Octisalate and Avobenzone, will absorb the sun’s rays and can, in some instances, offer better protection than mineral based sunscreens. These will take about 20-30 minutes to absorb into your skin, however, so you should not go out into the sun right after applying. 

A mineral sunscreen uses active natural ingredients such as Titanium Dioxide and Zinc Oxide, which create an actual physical barrier between your skin and the sun’s harmful rays. There has, in recent years, been some debate about using nano-particle (very very small) mineral sunscreens that tend to work faster, and the science has proven that they are perfectly safe to use. Because the mineral based sunblock creates a barrier immediately, you should be able to go out in the sun much faster than when using a chemical-based cream. Another benefit? They’re perfect for those with sensitive skin or skin-barrier issues. Last, but not least, because mineral sunblock is made with natural active ingredients, it is rated “reef-safe,” meaning, next time you want to go snorkeling on holiday and you don’t want to harm the fish or coral reefs with chemicals that don’t occur naturally in their habitat? Mineral sunscreen would be a good choice.

Rovectin Anti-Irritant UV Defense Tinted SPF 50+ PA+++

How much should you be using?

Recently, Gwyneth Paltrow horrified a bunch of dermatologists after an April 2021 post where she sparingly applied a pea sized amount of SPF to her face, and stated that she mainly covers her “nose and under her eyes”, where she feels she gets the most exposure. This amount and style of application is basically useless, however. The amount of sunscreen you should apply to your face and neck daily should be about a teaspoon. Bear with us, we know this sounds like a lot, but the sunscreen is here to keep you wrinkle, sun damage, and eventually cancer-free. Don’t be stingy, we know you are generous :)

Other Tips to Protect Yourself From the Sun

  • Don’t forget to wear sunblock even if you’re not going outside. The sun’s rays are powerful and penetrate through buildings. The same goes for cloudy or rainy days and especially, when traveling on an airplane!

  • Wear a hat or a visor - anything that will put a bit more protection between you and the sun’s rays. That also goes for your body: invest in a rash guard (swimshirt) to avoid sun damage to your chest when you’re at the pool or beach!

  • Make sure to reapply sunscreen - once you’ve applied in the morning you have a maximum of two hours (if you’re not doing strenuous activity or swimming) before you need a bit of a top up. Carry SPF with you if possible to make sure you can reapply easily. 

  • Wear sunglasses - your eyes can also be damaged by UVA and UVB rays!

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