These creams have some chemical that blocks the UV with some capacity, say a factor of 50. Why can’t I apply two layers of this cream to now get a 100 factor equivalent protection?
I asked the chemist at the store and they said it’s not how it works and that the highest protection factor they have is 75 (which was super expensive).
What gives?
Edit: Thank you for those super informative answers.


SPF rating is subjective at best and not a regulated term in many countries.
Australia is a place where it is a regulated term and a test by Choice showed that 16 of 20 products failed their rating and several have since been recalled.
https://www.choice.com.au/health-and-body/beauty-and-personal-care/skin-care-and-cosmetics/articles/sunscreen-test
Back to your original question which is answered in the article
No way! So like I’d be be paying exponentially more for an additional 0.6% if I brought the SPF75!
Damn.
Yeah but any power gamer loves this math because that 0.6% is still a nearly 30 percent damage reduction compared to the lower grade sun armor so you’ll be stomping those pubs that don’t persue it.
Does higher SPF cost more where you live? I just bought both 50 and 100 and they were the same price
Australia? Cause it seems that there SPF is just a marketing tactic.
Texas. HEB
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Yep. Welcome to capitalism, where the bigger made up number actually mean very little in real terms.
Everyone knows that Societ sunscreen was the pinnacle of effectiveness and issued according to need.
I looked up sunscreen recommendations on Consumer Reports and virtually every sunscreen didn’t perform as well as advertised in CR’s lab tests. CR’s top rated sunscreens all happen to be marketed for kids/babies oddly enough.
You get sunburned: “oh, silly me, I must have forgot to reapply”
Your baby gets sunburned and spends the next 72 hours crying: “I will murder the CEO of Johnson & Johnson”
Good writeup, yo
so if u do two spf 50 layers u should get spf 2500.
but in practice the second layer won’t be as thick…
Depends how you apply it. I smear it on like butter.
…How do you smear butter on your skin then?
Like suncream
Careful of sunscreen stains. I apply 2 thin layers under air conditioning to minimize the moisture and allow it to fully dry.
Whereas I dip myself in a big tub of it, like a Mekon at dinner time
Yeah, like that, but the cream is a bit lighter and I’m a bit darker
This is the way to do it. You need a lot of it to get the full protection that it offers.