Sunshine is wonderful and has many benefits, but as almost everyone surely knows, it also has its dangers and drawbacks. This article covers the proper use of sunscreen, sheds light on the biggest myths related to sunscreen use, and how you can best protect your skin 🌞

Korean sunscreens have gained popularity worldwide due to their innovative, lightweight, and skin-improving formulas as well as effective UV protection factors. Explore Yeppo's sunscreens here!

Why it is important to use sunscreen? 

If you want to take care of your skin, using sunscreen is essential for your skin's health. UV radiation can damage skin cells and cause premature aging as well as increase the risk of skin cancer. Additionally, not using sunscreen means missing out on many benefits of your skincare products. Not only will your skin suffer more damage from the sun if left unprotected, but many of your skincare products would also benefit from filtering UV radiation from the skin. If you use AHA acids like glycolic or lactic acid in your skincare routine, you should always remember to protect your skin from the sun, as these acids make the skin more sensitive to sunlight.  

Many mistakenly believe they should only use sunscreen if their skin burns easily in the sun or if they spend long periods in direct sunlight. However, using sunscreen is important for everyone, regardless of whether they burn easily or not. Even if your skin does not burn, the sun's UV radiation still damages the skin; you may just see the effects much later. It is good to note that in darker skin, burning and tanning may not be easily noticeable, so the effects caused by it can go unnoticed.

What effect does the sun have on skin aging?

Sunlight is one of the biggest factors affecting skin aging and, most importantly, its effects are easy to minimize.

The sun's UV radiation consists of rays of different lengths, the most talked-about being UVA and UVB rays, which penetrate different layers of the skin and can cause damage at the cellular level. UV radiation also promotes the formation of free radicals, which in turn damage skin cells and collagen fibers. This leads to skin sagging, wrinkle formation, and pigmentation changes.

It is important to understand about UV radiation that the damage it causes is always permanent. Whether it is just tanning or sunburn, the change happening in the skin always indicates that skin cells have been destroyed. The most significant signs often appear only after decades, which is why many think the damage caused by sunburn is not that severe.

1. Breakdown of collagen and elastin

Collagen is a protein that, together with skin elastin, gives skin its firmness and elasticity. UV radiation breaks down collagen fibers and elastin in the skin, leading to sagging and wrinkle formation. This process happens over years and makes the skin look older than it actually is. 

2. Pigmentation changes

Sun UV radiation can cause skin pigmentation changes, such as liver spots and darkening of the skin. This happens because UV radiation stimulates melanin production in the skin, which can cause uneven skin tone and discoloration. 

These pigmentation changes are especially pronounced on skin that already has more melanin, meaning darker skin tones.

Why do I need sunscreen when my skin is dark?

Although darker skin has natural protection against the harmful effects of the sun due to higher melanin levels, it does not provide complete protection against UV radiation. Melanin is the pigment that gives skin its color, absorbs and breaks down UV radiation, and helps prevent radiation from penetrating deeper layers of the skin. This explains why dark skin burns less often and more slowly than light skin. The UV protection provided by melanin is estimated to be at most SPF 8, which is a very small amount.

However, UV radiation can still damage skin cells and increase the risk of skin cancer even for darker skin types. Burning is also not as noticeable as with lighter skin, which can delay noticing early signs of skin cancer and seeking treatment. Pigmentation and liver spots are also common sun-related skin issues for darker skin, which could be more easily prevented by using sunscreen.

What does the PA rating on sunscreens mean?

You are probably familiar with SPF and UVA and UVB labels on sunscreens, but Korean sunscreens also feature the PA rating.

PA stands for "Protection Grade of UVA." It is a scale that measures the level of protection a sunscreen provides against UVA rays, which are linked to premature skin aging and other harmful effects. UVA rays are longer than UVB rays and cause less burning, but they still significantly affect skin aging and the formation of pigmentation disorders.

The PA scale classifies sunscreens into four levels: PA+, PA++, PA+++, and PA++++. The higher the PA rating, the better the sunscreen protects against UVA rays.

PA+: weak UVA protection
PA++: moderate UVA protection
PA+++: good UVA protection
PA++++: excellent UVA protection

Combining a high SPF and a high PA rating ensures comprehensive protection for the skin against the harmful effects of the sun.

The most common myths about sunscreen

Especially on social media and discussion forums, you often encounter claims about sunscreen use that are purely myths. Misinterpreted scientific studies also cause many misunderstandings that are difficult to correct. Let’s go through the myths that are important to debunk!

Myth: Physical sunscreen reflects UV rays off the skin

This is about 90% a myth! Physical (inorganic) sunscreen works largely the same way as chemical (organic) sunscreen. Both absorb harmful UV rays and convert them into a safer form for the skin and environment. Both produce a very small amount of heat in this process, but the amount of heat is so small that it has no effect on the skin. So you can choose either one if your concern is melasma or rosacea – pick the one that suits your skin best.

Inorganic UV filters do reflect a very small amount of radiation, only about 5-10%, so the mechanism of action is largely the same for both. 

Myth: Sunscreen is not needed in the Nordic countries

This is a persistent myth in the Nordic countries. Our UV index is so low that using sun protection is unnecessary – or is it? In the Nordic countries, the UV index is close to 0, so the need to protect against skin cancer is not essential. The general recommendation is to protect yourself when the UV index is above 3 – which applies in Finland from late spring to early autumn. This is a recommendation for when you should start protecting yourself at the latest. Protection advice is not given because of premature skin aging but to avoid the risk of skin cancer. If you want to take good care of your skin, it is advisable to protect yourself from UV radiation. 

About 12,000 Finns are diagnosed with skin cancer annually, and in Sweden, there are around 4,000 melanoma cases each year. The number of skin cancers is believed to be rising because many people in the Nordic countries feel the need for protection is low and do not protect themselves adequately during vacations. 

Myth: Sunscreen stops the skin from producing vitamin D

Vitamin D is essential for our health, and the ways to get it are either through sunlight or vitamin D supplements taken internally. One of our skin’s functions is to produce vitamin D from sunlight, so can sunscreen prevent vitamin D production? 

This is a myth based on research. Few of us protect ourselves from the sun so thoroughly that every single part of our body is 100% covered. The skin produces vitamin D even if part of it is protected, because in reality some areas are always left unprotected. 

Myth: Sunscreen prevents tanning

How can this be a myth? The purpose of sunscreen is to protect the skin and prevent sunburn. But in practice, many apply too little sunscreen or don’t reapply it throughout the day. If you stay in the sun long enough and the sunscreen’s protection has weakened (due to rubbing your face, sweating, swimming, etc.), you may still tan or even burn. That’s why it’s important to reapply sunscreen throughout the day and use enough of it. Sunscreen is also not the only way to prevent burning - hats, clothing, and sun umbrellas also provide effective protection. 

Myth: Chemical sunscreen must be applied to clean skin

You may have encountered the claim that chemical sunscreens must be applied to clean skin and allowed to absorb to work. This is not true; chemical sunscreens work just as well on top of other products.

Sunscreen works best when applied in a sufficiently large amount on as even a surface as possible, and the skin is not touched unnecessarily after application. For this reason, all skincare products should be applied before sunscreen.

It is also recommended to avoid excessive rubbing of sunscreen into the skin to prevent accidentally reducing its effectiveness. Apply the product evenly on the skin and let it absorb calmly.

Myth: Sunscreen needs to be absorbed into the skin before it works

This is not exactly true. Sunscreen should be applied before going outside, but no sunscreen needs time to "activate."

The traditional 15-minute waiting time recommendation is based on allowing the product to settle on the skin and not, for example, be wiped off by clothing or movement. Both chemical and physical sunscreens need time to settle on the skin and form a durable "protective layer" before applying makeup. If you don’t wear makeup, you don’t need to wait; the sunscreen works immediately—just avoid rubbing your skin unnecessarily at first. How long this takes depends on the sunscreen’s formulation, so follow the product instructions. Most sunscreens recommend 15-20 minutes, though sometimes less may be sufficient. 

Myth: The SPF in foundation is enough to replace sunscreen

Sunscreen should be applied at 2 mg per square centimeter of skin to match the SPF indicated on the product. This amount is so large when used as foundation that in reality, probably no one applies that much foundation on their face. So, since you use much less foundation on your face than, for example, sunscreen, you likely get less than a quarter of the protection stated on the container from the foundation. The SPF in foundations mainly serves as excellent additional protection alongside traditional sunscreen.

Myth: The SPF label on a moisturizer is not as protective as a proper sunscreen

Have you ever tried moisturizing Korean sunscreens (hello Round Lab Birch Juice Moisturizing Sunscreen)? If you have, you probably wouldn’t be able to tell the sunscreen apart from a regular moisturizer in a blind test.

Sunscreen and moisturizer are basically the same thing, as long as you apply a sufficient amount of cream and the facial moisturizer has a high enough SPF for your needs.

Myth: Sunscreen protection disappears within 2-3 hours

Sunscreen protection does not wear off because the UV filters become inactive. The reason sunscreen is generally recommended to be reapplied every 2-3 hours is that as you move, sweat, dress, and as your skin produces sebum, the sunscreen’s surface becomes uneven over time. Some sunscreen also evaporates from the skin and is absorbed, thinning and weakening the protective layer. All this leads to the sunscreen no longer being even, thinning out and forming gaps, leaving the skin less protected.

You should always reapply sunscreen every two hours, starting from when you first put it on your skin, not counting how long you have been in the sun.

Myth: Physical sunscreens work better than chemical ones

The effectiveness of sunscreen depends solely on the protection factor it offers and proper application. Whether it’s a physical or chemical sunscreen, both must be thoroughly tested and meet the same legal requirements for effectiveness.

Whether you choose a chemical or physical sunscreen depends entirely on your personal preference – you can only find the most suitable product for your skin and preferences by testing.

Myth: Physical sunscreens are more natural than chemical ones

Physical sunscreens are also processed and are not significantly more natural than chemical ones. Often, so-called mineral sunscreens include synthetic ingredients to prevent a clumpy texture and ensure even application on the skin. The ingredients used in physical sunscreens require extensive processing, which also has some environmental impact. Ingredients in chemical sunscreens that may cause skin irritation are mainly older UV filters like avobenzone and homosalate. Koreans prefer new, modern UV filters in their sunscreens, which are more effective but less irritating to the skin.

Korean sunscreens often feature so-called hybrid protection, which combines both chemical and physical UV filters. This way, you get the best of both worlds; the lightness of chemical sunscreens and the gentle pore-smoothing effect of physical ones.

Myth: Sunscreen is not needed indoors

The need to use sunscreen indoors depends on where you live, the type of window glass, and the intensity of UV radiation. 

Many in the Nordic countries do not need sunscreen indoors, especially from autumn to spring, because window glass filters out most UVB rays. However, windows still allow a large portion of UVA rays, which are the main cause of premature skin aging and skin hyperpigmentation. UVA radiation can also cause skin burning. If you spend most of your day near a window or your house has large skylights, using sunscreen is recommended to prevent premature signs of aging. 

👉🏼 Some windows have separate UV protection that blocks over 99% of UV radiation. These also help regulate indoor temperature, so their popularity has increased. 

Myth: Using sunscreen is harmful to the environment

Understandably, sunscreen is not good for the environment if hundreds of liters are poured into the sea. But in normal use, its impact on environmental pollution compared to other larger factors (such as global warming, eutrophication) is minimal. 

Scientific tests measuring the negative effects of sunscreen on marine life such as jellyfish and corals have been conducted in ways that do not correlate with real life. Tests examining the amount of sunscreens and UV filters used in real sea conditions have shown the detected amounts to be very small. Amounts may have been higher in areas without currents and during crowded times.

We encourage everyone to make responsible choices as much as possible, but not at the expense of your own health.

Myth: Sunscreens are hormone disrupting

This is a difficult topic and not exactly a myth, but something that is important to clarify.

Studies that have examined the effects of certain sunscreens (especially oxybenzone, which has been on the market since the 1970s) on hormone function have been conducted in vitro (not in living organisms, e.g., in test tubes) and on animals. These studies have shown that some sunscreens bind weakly to hormone receptors. There is not yet clear evidence of what this effect is or whether it is sufficient to cause any effect in the body. Currently, research does not show direct danger; further studies are needed to confirm this, including real-life tests on actual humans.

If you want to play it safe, choose new technology UV filters such as Ethylhexyl Triazone (Uvinul T 150), Drometrizole Trisiloxane (Mexoryl XL), Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine (Tinosorb S). The advantage of these new filters is also that they absorb less because their molecular size is larger.

Myth: Nanoparticles in physical sunscreens are dangerous to the body

Partly true. Nanoparticles of zinc oxides and titanium dioxides can possibly cause reactions in the body, especially when combined with UV radiation. However, these nanoparticles have not yet been shown in studies to penetrate deeply into the skin, only reaching the very top dead layer of the skin. It is theoretically possible that they could be absorbed deeper through broken skin, but there is no detailed research on this yet, and so far they are considered safe for human use.

Looking for tips on finding a good sunscreen?

Credits: 

Sunscreen E-Summit. The Eco Well. Video. 4/1/2026.

Hormone Disrupting Beauty!? The Eco Well. Video. 4/2/2026

Melanoomatilasto paljastaa karusti, millaisia vaikutuksia aurinkoturismilla on. Docrates Mehiläinen 2022.

American Academy of Dermatology Association,

Skin Cancer Foundation,

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Harvard Health Publishing.