A nominal SPF of 50 often acts like SPF 15-25 on a real face, because almost no one applies the amount recommended in the lab test. This is one of the most important things to know before reaching for sunscreen. Find out what these numbers really mean and how to use the sunscreen to ensure real protection!
What you should know about SPF:
Number and repetition of applications matter more than chasing a higher SPF number.
SPF is Sun Protection Factor. This number describes how many times longer sun-protected skin can stay in the sun before redness appears, compared to unprotected skin. SPF refers primarily to protection from radiation. UVB, so a high number alone says nothing about UVA protection.
Therefore, a good face cream should have a wide range of protection, like ours SPF 50 sunscreen Restart SPF 50 from the 365 line – a filter with SPF 50 and PA++++ protection, with soothing extracts of centella asiatica, aloe and cucumber.
Sunscreen limits the amount of ultraviolet radiation that reaches living skin cells.
The division into chemical and mineral filters is sometimes wrongly simplified: organic filters absorb UV and convert it into a small amount of heat, while zinc oxide and titanium dioxide also largely absorb UV, not just reflect it.
In practice, what matters for the skin is:
Solar radiation reaches us in two main forms – UVA and UVB – and each affects the skin differently. UVB has a shorter wavelength and is responsible for immediate effects: redness, burns, and in extreme cases, blisters. It is this type of radiation that the SPF rating on sunscreen packaging protects us against.
UVA, on the other hand, penetrates deeper, reaching all the way to the dermis, and has a more insidious effect. While it doesn't cause immediate symptoms, in the long run it leads to loss of elasticity, wrinkles, discoloration, and a weakening of the skin's protective barrier.
That's why it's so important to choose products labeled "broad spectrum" or with the UVA protection symbol. Only then can you be sure your skin is fully protected.
SPF numbers don't increase linearly, and this is the most common source of confusion. The difference between subsequent values decreases the higher you go on the scale. Below, we've broken down the specific values.
SPF 15 absorbs approximately 93% of UVB radiation. This level is sufficient for short-term exposure, but too low for skin prone to discoloration, during treatments with active ingredients, or with prolonged sun exposure. For daily use, this is a minimum rather than the ultimate choice.
SPF 30 blocks about 97% UVB, while SPF 50 blocks just over 98%. The difference in the lab is small, but since most people apply too thin a layer, the higher nominal SPF acts as a buffer to compensate for application error. For skin prone to discoloration, in post-treatment care, or when using retinol. SPF 50 is a reasonable choice.
The difference between SPF 50 and SPF 100 is marginal, as both block more than 98% UVB. In the European Union, sun protection ratings end at 50+, so very high numbers don't guarantee better protection. Make sure the product has a broad spectrum of activity, uses the right amount, and reapply throughout the day.
The PA scale describes the level of protection against UVA, which penetrates deeper into the skin and is responsible for photoaging and some discoloration. The more pluses, the higher the protection, up to PA++++. UVA protection should be at least one third of the declared SPF value, so a high SPF number alone isn't enough. Therefore, a good face sunscreen should be PA++++, confirming a high level of UVA protection.
Sunscreens are divided into two main types: chemical and mineral – and each of them works on a different principle.
Chemical filters absorb UV radiation and convert it into heat, which is then released through the skin. They are lightweight, easily absorbed, and do not leave a white cast, making them popular in daily skincare.
Mineral filters, also known as physical filters, contain zinc oxide or titanium dioxide particles that reflect and disperse sun rays before they reach the skin. They are gentler and less likely to cause irritation, making them recommended for those with sensitive, reactive, or rosacea-prone skin.
The choice between them depends on your skin type and preferences – if you have oily skin, a chemical filter may be more convenient, while for sensitive skin, a mineral one is better.
The effectiveness of an SPF cream depends largely on how much product you actually apply to your skin. Most people use far too little, which reduces the actual protection by up to half. Hence the two-finger rule, which helps you measure the right amount of product for your face and neck.
Squeeze the cream along your index and middle fingers. – from base to tip. This amount should be enough to thoroughly cover your entire face, neck, and décolleté. Apply the cream to clean skin as the last step of your skincare routine, about 15-20 minutes before going outside. Give it time to fully absorb and create a protective layer to photoprotection it worked.
Not every cream has SPF under makeup it will work for everyone – Skin type is crucial when choosing the right formula. Oily and combination skin needs a light texture, preferably in the form of a gel or mattifying fluid that won't clog pores or leave a greasy shine.
Dry skin will appreciate richer creams with added moisturizing ingredients like hyaluronic acid or ceramides. Sensitive skin requires formulas free of alcohol, artificial fragrances, and potentially irritating ingredients – mineral filters are best here.
It is worth remembering that SPF is the most important step in skincare. Our products are designed for a variety of skin types, combining effective protection with everyday comfort.
Photoprotection This is the foundation of the fight against discoloration, as the sun increases the production of pigment in the skin. Without a consistent filter, even the best brightening ingredients work against the grain, and new spots appear faster than old ones disappear – this applies to sun spots and the more severe melasma.
By melasma UV protection alone may not be enough. A 2014 study by Castanedo-Cazares' team on melasma showed that visible light, not just UV, also intensifies pigmentation. So remember that tinted filters with iron oxides provide better support – this is an important tip when sun discoloration.
Daily photoprotection It actually slows down visible skin aging, not only protects against sunburn. In 2013, Australian researchers, after many years of observation of over 900 people, showed that daily use of the filter significantly reduces the progression of visible skin aging. photoaging compared to occasional use.
It's worth keeping your expectations realistic: the filter slows down new damage but does not reverse existing wrinkles. Therefore, it works best as part of a consistent routine, and its importance increases with age – more on that, Is SPF valid after 30? year of life.
Vitamin C is not a filter and does not replace SPF, but it complements it in your morning routine as an antioxidant that neutralizes free radicals that are created by exposure to the sun despite the sunscreen applied. The combination of vitamin C, E and ferulic acid increases the skin's antioxidant protection.
The order is simple: first vitamin C serum, then filter. Our C / E / Ferulic Serum combines stable vitamin C with ferulic acid and vitamin E, so it works in synergy as described. Note that good vitamin C for the face makes sense only together with the filter, not instead of it.
Retinol and SPF should be used together, but at different times of the day. Vitamin A derivatives improve the condition of skin showing signs of photoaging, but they can initially cause irritation, so they should be applied in the evening., and the filter in the morning.
Consistent photoprotection is especially important during retinol treatment - our retinyl serum combines stable Retinyl Retinoate with peptides and niacinamide, making the formula effective while also being designed with low irritation potential in mind. Anti-aging treatment without a filter is pointless – more tips in the text about retinol in daily care.
Even the best sunscreen won't work if you make basic mistakes in application. The first and most common problem is using too little product – most people apply around the recommended dose, which drastically reduces the level of protection.
Another mistake is neglecting certain areas of the face, especially around the ears, jawline, and eyelids. Another problem is applying SPF only in the summer – UV radiation is present year-round, even in winter and on cloudy days. Our cosmetics are designed to work perfectly with sunscreen and enhance its protective effects.
The best sunscreen is one that's applied regularly, in the right amount, and repeated throughout the day. The SPF value and PA label are important, but consistency is key to achieving the real results. Sunscreen is the last step in your morning skincare routine, after moisturizer; if necessary, compare the best SPF filters for your skin type and see why sunscreen creams are so important. If you're looking for a sunscreen that combines SPF 50, PA++++, and soothing ingredients, reach for Restart SPF 50!
The filter should be renewed every 2 hours when exposed to the sun continuously and after any intensive contact with water or sweat.
The main difference is the degree of UVB blocking, SPF 50 provides higher protection (50% more blocked radiation than SPF 30), which is crucial for fair skin, in hot weather and with high sun exposure.
No – to get the claimed protection, you would have to use several times more product than you normally apply with your makeup, so always use a separate sunscreen as a base.
SPF stands for Sun Protection Factor, which tells you how long you can stay in the sun without getting burned compared to unprotected.
It doesn't block completely - SPF 50 lets through about 2% of UVB radiation, so tanning still occurs, but much slower and safer than without protection.
No – SPF cream should be the last step of your skincare routine, applied over previously applied serum and moisturizer, just before makeup.
SPF 50 blocks just over 98% UVB, so some UV rays always reach the skin.
UVA radiation penetrates clouds and is active all year round, so a filter is needed even in winter and on cloudy days.
SPF 30 means that the filter absorbs about 97% of UVB radiation, more than SPF 15, but still not full protection.
SPF describes protection mainly against sunburn-causing UVB, while PA indicates the level of protection against UVA.
Regular photoprotection reduces the risk of some skin cancers, although it does not provide a 100% guarantee.
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