When it comes to sunscreen, applying it once under your makeup may not be enough to protect your skin from sun damage. And we all know by now that sun damage cause up to 80% of wrinkles, discoloration, and inflammation, and not to mention the risk of developing skin cancer.
So how often should you reapply sunscreen?
Think of your sunscreen as a laptop battery, the longer you stay in the sun, the less and less effective your sunscreen become. Sun light slowly breaks down the UV filter, decreasing its protection power over time.
If you work in the office and wear SPF30, the sunscreen can probably last you all day without having to reapply.
If you stay in the shade, you can reapply every 3–4 hours, depending on how light your skin is.
If you spend lots of time outside, to maximize your sun protection, make sure you apply a generous amount of sunscreen and reapply very 2 hours .
If you are in the water or play sport, reapply every hour.
When picking your sunscreen, look for one that is wide spectrum. While SPF indicates how much UVB rays the sunscreen blocks, wide spectrum indicates that the sunscreen blocks both UVA and UVB rays. UVB rays is what responsible for sun burn, skin cancer. UVA ray penetrates deeper and causes collagen breakdown (aka wrinkles!) and dark spots.