Melanin production is skin’s natural response to defend skin against UV damage, but over time, it will lead to hyper pigmentation in the form of dark spots and patches with you’re older. The best way to protect skin against UV damage is to apply sunscreen – besides preventing the formation of dark spots, sunscreen can also defend against damage to skin collagen and elastin, hence delaying the effects of ageing.
There are two different types of sunscreen: chemical and physical. Chemical sunscreens often contain active ingredients like Octylcrylene, Avobenzone, Octinoxate, Octisalate and Oxybenzone. They work to absorb UV rays and are usually colourless and odorless, making them ideal for adding into foundations and makeup primers.
Physical sunscreen contains actives like zinc oxide and titanium dioxide, which reflects and blocks UV rays. They are often responsible for leaving a white cast after application.
There are pros and cons for both chemical and physical sunscreen, with the former causing irritation for those with skin sensitivity and being effective against the sun only 20 minutes after application. Physical sunscreens, on the other hand, defend skin immediately after application but the texture can be a little off-putting as they leave a white cast. Neither sunscreen is superior over the other, and the key is to pick one that works for you depending on your skin type and lifestyle.
It is also useful to note that sunscreen photo-degenerate, meaning they start losing their efficacy once exposed to the sun. The general rule is to apply it once every two hours, so as to maintain optimal level of UV protection. While regular sunscreen fluids make it difficult to reapply, especially over makeup, spray-on sunscreens have proven to be really useful in that aspect.