Sunscreens contain filters that shield the skin against the Ultraviolet (UVA -UVB) rays. UV rays can cause sunburn and premature skin aging . They also increase the risk of skin cancer.

First of all, a couple of facts about the UV rays and the way they act. UVA rays have longer wavelength, can penetrate the deeper layers of the skin as well as the glass causing damage and accelerated aging. UVB rays have shorter wavelength, don’t penetrate as deeply as UVA but damage the outermost layers of the skin which leads to sunburn. When DNA is damaged over time, cells may grow out of control and could lead to skin cancer. UVC have the highest energy but they are blocked by the atmosphere’s ozone layer.

It is highly recommended to choose a sunscreen that protects from both UVA and UVB rays (broad-spectrum SPF). SPF means SUN PROTECTION FACTOR. A higher SPF means that you can be sun exposed for a longer time without getting sunburnt. You  should reapply it every two hours especially after swimming or sweating. It is advised to use one with SPF30 or above. Preferably SPF50. Must be water-resistant as well.

Sunscreens or sunblocks contain filters that can be organic or mineral chemical substances.

Mineral chemicals create a protective barrier on the skin, they act on the surface. On the other hand, the chemical ones are absorbed by the skin to protect the deeper layers.

Sun protection is essential all year long. If you stay indoors, next to a window to the direct light, you should also apply your sunscreen . UVA rays can penetrate the glass whereas UVB are blocked.

Sunscreens are generally safe according to the existing studies. A good product would contain also low doses of antioxidants to enhance and ensure its protecting action. They generally contain tocopherol (vitamin E). You may also combine your sunscreen with a serum containing the coenzyme Q10 ( ubiquinone) that enhances the action of the sunscreen. This is what I generally do. You can also apply your vitamin C serum before the sun protection.

A common concern is whether sunscreens can cause acne or pimples. The short answer is yes, but under certain conditions, such as:

The sunscreen has a rich texture and leaves the skin feeling oily. However, this could happen with any cream and this is not a reason not to use it.

The skin is exposed to dirt and dust. When you return home, your skin must be  thoroughly cleansed to remove sunscreen and dirt.

If you follow the rules of hygiene, there shouldn’t be any particular issue.

There has been a great deal of discussion regarding the filters used in sunscreens and whether they are stable or disrupt the function of the endocrine glands.

These filters are:

Oxybenzone (benzophenone-3) : Blocks the UV rays but there is a big concern about it. This filter can disrupt the endocrine system and cause skin  irritations and allergies. It is also dangerous for the marine system and especially to corals.

Octinoxate (ethylhexyl methoxycinnamate):  Protects against the UVB rays but not the UVA. It is not stable and should be combined with other ingredients to be stabilized. It may also disrupt the function of endocrine glands. There are also risks for the marine life. It is generally considered safe at certain concentrations.

Avobenzone (Butyl Methoxydibenzoylmethane): This filter can be effective against UVA, however it is unstable in the sun light. This is the reason that the sunscreen should be reapplied after a couple of hours. Possible solutions are to combine it with other filters or encapsulate it. It is generally safe.

Homosalate: It is weak filter not stable to sunlight. Ha to be combined with other filters.  It may also disrupt the function of the endocrine glands and has not yet been studied for its safety in long-term use.

Octisalate (Ethylhexyl Salicylate): It is used to stabilize other filters but can cause skin irritation and allergies in people with sensitive skin although it is generally considered safe.

Octocrylene: Mainly protects against UVB. As a filter is not very stable. It is generally used to stabilize other filters. May cause irritations to people with sensitive skin.

Dioxybenzone:(benzophenone-8): Absorbs the UVB rays and somehow the UVA (short-wave). It is generally safe but can cause allergic reaction.

Sun protection is absolutely necessary. Nevertheless, if you are concerned about potential allergic reactions, do first a patch test. Ask for free samples before you buy a sunscreen in order to see how your skin will react. There are many sunscreen products on the market and you will definitely find one that suits you.

The difference between chemical and physical filters:

Chemical filters are absorbed by the skin and create a layer that acts as a filter for UV rays. They take 20-30 minutes to be activated. This is why the instructions for use, say that they should be applied 20 minutes before sun exposure. They have a better aesthetic effect. They don’t leave white cast on the skin like the mineral ones.

However, creams with chemical filters could cause skin irritation in people with sensitive and reactive skin since they penetrate the skin barrier.  In this case, prefer creams with natural filters.

Mineral filters due to titanium dioxide and zinc oxide leave white-gray residues on the face. They seem to be better for those with skin issues. They don’t penetrate the skin but create a protective barrier. Thus, they reflect the UV light.

In conclusion, the use of sunscreen is undeniable. Always choose the one that suits your skin type and doesn’t cause irritation. If you feel any discomfort on your skin, discontinue the use and choose another one more appropriate for your skin. Before purchasing sunscreen, it would be a good idea to ask for free samples to try it out. In case that you use a BB cream with a low SPF, do not rely on it, especially during the summer months.

Generally speaking, you should repeat the application every two hours but this is not always possible over makeup. However,, in case that you  swim, sweat, or towel dry, you should do it.