Skin Care Guide – Part 5

How to Choose Sunscreen?

All sunscreens can be divided into two general categories: physical and chemical sunscreens. Physical sunscreens contain either zinc oxide or titanium dioxide, and are generally considered safer, as their active ingredients neither chemically interact with your skin, nor penetrate into the blood stream. They work by reflecting or scattering UV rays.

On contrary, chemical sunscreens absorb UV light and do interact with your skin and may penetrate into your blood system. Hence there is a concern that chemical sun-blocks may alter chemical reactions in your body and thus affect your health. While studies of long-term side effects by chemical sunscreens are not available at this time, scientist and cosmetologists believe that the safe chemical sunscreens should contain one or a few of these active ingredients: homosalate, Mexoryl SX (ecamsule) and phenylbenzimidazole sulfonic acid (also called ‘ensulizole’).

Whether you go for physical or chemical sunblock, the right sunscreen must meet the following criteria:

  • Comprehensive. Give you complete protection from both UVA and UVB radiation. It should have SPF >= 15 (measure of protection against UVB) and PPD >= 10 (measure of protection against UVA), which is equivalent to blocking at least 90% of UVA.
     
  • Safe for Health. It should be non-comedogenic (doesn’t contain pore-clogging ingredients that might cause acne), non-irritating for your skin and should not cause any unwanted biological effects such as hormonal changes in the body.
     
  • Suitable for You. Suitability of sunscreen for you is mainly determined by two factors – your skin complexion (or, more precisely, skin phototype) and the conditions of use. There are six skin phototypes, but roughly speaking if your skin is too pale or fair, you need sunscreen with SPF30 or higher, whereas for darker skin owners SPF15 would be enough for most situations. By “conditions of use” we refer to climate and/or water-exposure. If you are going to swim or bathe, or if you sweat a lot, then you need sunblock that is sufficiently water resistant and you need to re-apply it every 40 to 80 minutes depending on the strength of its water resistance (read and follow the instructions).

Other desirable properties the right sunscreen should have are:

  • It should be chemically stable, and neither degrade under sunlight nor react with other common cosmetic ingredients.
  •  It should stick well to your skin and do not come off or wash off easily.
  • There should be some published evidence that most of the essential and additional criteria discussed above are indeed have been met and confirmed by clinical research.

 We do not recommend any particular sunscreen here because new clinical evidence may come and go that will prove or disapprove the effectiveness and safety of certain sunscreen ingredients. Besides, there is no one that ‘fits all’, and thus you have to do your ‘due diligence’ and find a sunscreen that is suitable for both your skin type and conditions of use sticking to the guidelines we gave you above.

Finally, remember that no sunscreen fully protects you from UV radiation of sunlight and the best protection you can offer yourself is to avoid sun-exposure as much as possible or, when it’s unavoidable, seek shade and wear protective clothing that covers most parts of your body.

.If you have any questions or comments on how to choose sunscreen, you are welcome to leave them below.

Skin Care Guide Part 6 – How to apply sunscreen correctly?

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