Using sunscreen correctly is very important to your skin. If you choose good sunscreen products and use them correctly, your skin can get more protection and thus looks younger with time.
- Apply sunscreen during the day all year round. The UV radiation you get through the window, during a short walk outside, and when you are driving can add up day by day. For your lifetime, they can be more than what you get on the beach. While sun-protection clothes, hats and umbrellas are helpful, they don’t block 100% UV radiation. Do remember that UVA can pass through windows and clouds.
- Choose a sunscreen with UVA protection. Commonly used sunscreens block UVB but are virtually transparent to UVA, which makes up to 90 to 95% of ultraviolet energy in the solar spectrum. By blocking UVB, sunscreens reduce tanning and prevent sunburn. On one hand, tanning and sunburn are skin damage of certain levels. On the other hand, they are, to some extent, skin’s natural accommodation to sunlight. Sunscreens that block UVB prevent this process and thus may permit excessive exposure of the skin to UVA. And then the damage resulting from UVA is greater. This makes some people believe that the incidence rate of the skin cancer has risen with the use of sunscreens, which is not true. So make sure your sunscreen has at least one of these as its active ingredients: Avobenzone (also called butyl methoxydibenzoylmethane), Zinc Oxide, Titanium Dioxide, or Mexoryl SX (also called ecamsule). Outside US, Tinosorb S (also called bis-ethylhexyloxyphenol methoxyphenyl triazine) and Tinorsorb M (also called methylene bis-benzotriazolyl tetramethylbutylphenol) are also approved.
- Use a sunscreen of SPF 15 or above, preferably SPF 30. A sunscreen of SPF less than 15 is not sufficient. Technically, the higher the SPF is , the longer the protection lasts. But sunscreens with overly high SPF sometimes irritate the skin or look too noticeable. So generally, SPF 30 to 45 is optimal.
- Apply sunscreen liberally. The dose used in FDA sunscreen testing is 2 mg/cm2 of exposed skin. This translates to approximately 1/3 of a teaspoon for the average adult face. Apply sunscreen to any exposed skin, not just the face.
- Reapply your sunscreen within two hours if you are under sunshine. If you don’t reapply, using sunscreen might cause more damage than not using it. If you have makeup and don’t want to mess it up with reapplication of sunscreen, I suggest you should at least reapply some powder with sunscreen. Keep in mind even sunscreens with the highest SPF don’t provide all-day protection. So you still need to reapply when you are outside for a long period.
- Avoid intensive or direct sunshine as much as you can. No Sunscreen blocks 100% of UV.