[Ashley]

Since it's starting to warm up for some of us, here are some tips for choosing the right sunscreen:

The Savvy Secret of Sunscreen

Andrea’s stumped by sunscreen: I was shopping today and realized just how many sunscreen options are available today. Neutrogena has a whole line of face sunscreens with SPF ranging from 45-80! How do I know how much SPF I really need?

Fore Brain’s fast answer:
The quick answer is that SPF (aka Sun Protection Factor) is generally a multiplier of your skin’s ability to resist burning. So if normally your skin burns after 12 minutes of sun exposure, applying sunscreen with an SPF 10 will increase the exposure time to 120 mins before you will get burned. This should help you pick out a proper SPF for your skin. Unfortunately sunscreen quality isn’t all in the SPF, so read on for other factors you should look for in a good sunscreen.
UVA UVB UVWhat?

Sunlight in outer space is composed of radioactive rays, which get filtered out by the atmosphere layers of the Earth. Of all the dangerous rays that the sun emits, the only ones that reach our skin are the UV rays. These rays fall into many categories but the ones we care about when discussing skin damage are UVA and UVB.
When they reach our skin, UVB rays stimulate Vitamin D production, appearance of moles, and can lead to sunburn with overexposure. There are more UVB rays in sunlight in the summertime when the sun is closer to the earth. UVA rays, are not as well known as UVB, and are responsible for tanning of the skin, as well as negative effects of sun exposure like as skin ageing and melanoma (a dangerous type of skin cancer). Unlike UVB, UVA rays are generally present at consistent levels throughout the year.
How do we protect ourselves from UVA and UVB?

This is where sunscreen comes in. Developed in the mid 1900s the aim of sunscreen is to limit sun overexposure and therefore minimize the negative effects and risks associated with sunbathing. The SPF rating that comes on sunscreen bottles is determined by an FDA required in vivo test which involves exposing volunteers’ skin to the sun until it sunburns and then evaluating the protection factor that the sunscreen gave that skin. The general rule is that the SPF is the multiplier of your skin’s normal resistance to sunburn, so if normally your skin would be sunburned after 12 minutes of direct sun exposure, with proper application of and SPF10 sunscreen, it will only get sunburned after 120 minutes.
A note about SPF ratings though. Some studies have shown that sunscreen’s protection factor doesn’t rise as evenly above SPF30 as it does in the ratings below. So for a long time sunscreens in the US were only allowed to be labelled 30+ because the numbers above 30 don’t represent sunscreen’s effectiveness the same way that SPFs 30 and below do. Recently this number has been raised to 50; however, you do need to keep in mind that still SPF50 isn’t twice as good as SPF25 as the number might have you believe.
But what about UVA?

Unfortunately, since the SPF test is mainly for the sunburn prevention properties of sunscreen, and those arise only from UVB, the official FDA test doesn’t shed any light onto how much UVA protection a sunscreen provides. Currently there are several skin pigmentation change tests available to test UVA activity and protection (since tanning is a result of the UVA rays stimulating melanin production and release), but they are not a requirement for sunscreen labelling in the United States. This is quite unfortunate, since UVA rays cause more long-term damage to skin like ageing and melanoma which is quite dangerous.
If you do want UVA protection in your sunscreen, look for products labelled as UVA/UVB broad spectrum, and don’t forget to check the ingredients; zinc oxide, titanium dioxide, avobenzone, and ecamsule (aka Mexoryl) are all effective at blocking UVA and have been approved by the FDA.


Source: The Savvy Secret Of Sunscreen | The Beauty Brains

Also, here are some great threads with recommendations from MUT members:
Sunscreen/sunblock recs
Favorite FACE Sunscreen
Best Sunscreen for Oily/Acne-Prone skin?
Sunscreen for face

[Dragonfly]

Thanks for sharing

[magosienne]

thanks Ashley !!

[La_Mari]

Thank you. I guess my Spf 80 isn't as much as I thought. I bought it cause it was the cheapest for the size.

[magosienne]

i think we also have to be careful about the number put behind the SPF. too high and people might think if it's SPF 500 (lol) i can only apply it in the morning and not reapply, when in reality you do need to reapply, especially after swimming.