Sunscreen: The best anti-ageing product

Let's talk about...Sunscreen: a topical product that absorbs or reflects the sun's ultraviolet (UV) radiation and thus helps protect against sunburn, wrinkles and sun spots. There are two types of UV radiation: UVA and UVB. UVA penetrates the skin more deeply and are associated with wrinkling and sagging whereas UVB is the main cause of sunburn.

To maintain a youthful looking face, prevention is better than cure. That is why applying sunscreen is an essential step of your beauty routine. 

How much Sunscreen do i need?
To get the advertised amount of SPF protection on a product's label, you need bout 1/4 tsp of sunscreen for your face alone. That's about a nickle-sized amount. 

UVA & PA:

PA stands for the protection grade of UVA.  

• PA+ provides some UVA protection with a factor of PPD 2-4. It protects sensitive skin against low to medium UV radiation.
• PA++ provides moderate UVA protection with a factor of PPD 4-8. It offers better protection from UVA rays and can be used by people with normal skin exposed to medium UV radiation.
• PA+++ provides good UVA protection with a factor of PPD > 8. It is the strongest grade of UVA protection. It is designed for normal skin under very strong or direct UV radiation.

UVB & SPF:

SPF stands for sun protection factor and measures the sunscreen's ability to prevent UVB.

• SPF 15 filters out 93 percent of all incoming UVB rays
• SPF 30 filters out 97 percent of all incoming UVB rays
• SPF 50 filters out 98 percent of all incoming UVB rays

How to apply Sunscreen to gain maximum benefit?

• Chemical sunscreens (those that contain avobenzone, mexoryl, oxybenzone, andoctocrylene etc) should be applied before you put on your moisturiser. This is because active chemical sunscreen ingredients need time to bind to the skin and that's why you apply sunscreen 20 to 30 minutes before heading out the door.
• Physical sunscreens (those that contain titanium dioxide and zinc oxide) can be applied after or before moisturiser, depending on preference. This is because unlike chemical sunscreens, they don’t need to be activated by any chemical reaction. 

-Emily

Reference: http://www.skincancer.org/prevention/sun-protection/sunscreen/sunscreens-explained