Should you use a moisturiser with SPF 20, a sunscreen with SPF 30, and a basis with SPF 15, what SPF do you get?
30 + 20 + 15 = 30.
Wait, what? Shouldn’t it’s SPF 65? Not fairly.
SPF math isn’t like common math. You may’t simply add up all of the numbers and count on superhero-level solar safety. Right here’s why:
Does Layering Sunscreens Improve Solar Safety?
Quick reply: No. However there’s extra to the story.
Layering sunscreens will NOT provide you with added SPF safety.
It’s a standard false impression, and truthfully, it is smart why individuals consider it. We’re used to pondering that extra layers = extra safety. Should you put on two sweaters, you keep hotter. Should you apply two coats of nail polish, you get a extra opaque coloration. However SPF doesn’t work like that.
Within the phrases of Mona Gohara, a dermatologist and an affiliate scientific professor of dermatology at Yale College, “SPF isn’t an equation. Your solar safety is barely as robust as your highest SPF.”
Within the instance above, the very best SPF is that of your sunscreen, SPF 30. That’s what you’re getting. It doesn’t matter what else you apply, that quantity received’t go up.
Why? Sunscreen works by limiting the variety of UV rays that hit your pores and skin.
- SPF 30 blocks 97% of UVB rays (those that trigger sunburn).
- SPF 50 blocks 98% (not an enormous distinction, proper?).
- SPF 15 solely blocks 93%, which suggests much more UV rays are nonetheless getting via.
- Even SPF 100 isn’t good. It nonetheless lets 1% of rays via.
Discover how the distinction between SPF 30 and SPF 50 is just one%? That’s why sunscreen layering doesn’t provide you with a magic enhance in SPF—it’s all about how a lot truly will get absorbed by your pores and skin.
Cease losing your money and time on stuff that doesn’t work. Click on on the picture beneath to obtain “Skincare That Works” and eventually get your greatest pores and skin day – each day.
How SPF Layering Works in Actual Life
Let’s see what this implies in sensible phrases utilizing the instance beneath.
Your basis has SPF 15. That enables 7% of UV rays to achieve (and hurt) the pores and skin. However you’ve discovered a moisturiser with SPF 20 beneath. That enables solely 5% of UV rays to achieve the pores and skin. 2% of the rays that made it via your basis are actually neutralised by your moisturiser.
However you have got a 3rd layer on. Your sunscreen with SPF 30 solely lets 3% rays via, neutralising an extra 2% that made it previous your basis and moisturiser with SPF.
The upper the SPF, the less % of UV rays attain the pores and skin. Sadly, no sunscreen blocks 100% of them. Even SPF 100 nonetheless lets 1% via.
If utilized appropriately, that’s…
Associated: Take A Quantity: What Stage Of SPF Is Proper For You?
How efficient is your sunscreen? Signal as much as the publication beneath to obtain the “Sunscreen Audit” Worksheet and discover out in case your sunscreen is de facto as much as the job:
Is Layering Sunscreens Ineffective?
Layering merchandise with SPF won’t add up SPF, however it could enhance your total protection.
That is the place layering can be useful. Although it doesn’t enhance your SPF stage, it could possibly show you how to cowl areas you may need missed the primary time round.
Let’s say you’re in a rush and making use of sunscreen rapidly. It’s straightforward to overlook a spot or two. These spots don’t have any safety and are truthful sport for UV rays.
However in the event you slather on a second SPF product, you have got extra possibilities of overlaying each little nook and cranny.
I personally don’t do that as a result of I’m very diligent with sunscreen software, however in the event you assume you want it, go forward.
WARNING! Should you don’t apply the really helpful quantity (1/4 of a teaspoon for the face alone), it’s possible you’ll get higher protection, however you received’t get the SPF said on the label.
Associated: Are You Making use of Sunscreen The Proper Method?
The Downside With Layering Sunscreen
Should you determine to layer sunscreens to get that additional little bit of solar safety, watch out.
Not all UV filters work properly collectively. Some can deactivate one another and compromise the extent of safety you’re getting.
That is the place it will get difficult. Sunscreen formulation are rigorously designed to stability completely different UV filters in a manner that makes them steady and efficient. However in the event you begin mixing completely different manufacturers and sorts of sunscreens, you can be messing with that stability with out even realizing it.
Particularly, beware of blending Avobenzone with Octinoxate, Zinc Oxide, and Titanium Dioxide.
Should you’ve simply checked the label of your fave sunscreen and seen it accommodates a number of of those (for instance, Avobenzone and Octinoxate), don’t throw it within the bin but!
Beauty chemists know all types of methods to make UV filters get alongside. For instance, by coating them in order that they provide the greatest safety with out getting too shut to one another.
It’s if you use separate merchandise that had been by no means meant to be blended collectively that you could be get in hassle.
One other challenge? Totally different sunscreens have completely different textures and finishes. Should you layer a thick, occlusive sunscreen beneath a light-weight gel components, it would tablet or rub off. Worse, in case your first layer is simply too greasy, the second layer won’t adhere correctly, which means you’re getting much less safety than you thought.
How To Layer Sunscreens The Proper Method
I’m not a fan of utilizing completely different sunscreens. It could assist, however except you recognize extra concerning the formulations and the way UV filters work together with each other, it’s possible you’ll cut back – relatively than enhance – solar safety. Ouch!
However in the event you nonetheless wish to do it, right here’s do it proper:
- Reapply the identical sunscreen twice: You continue to get the identical stage of SPF, cowl each nook and cranny, and run no threat of deactivating UV filters.
- Use two sunscreens with the identical (or related) UV filters: You’ll nonetheless get the very best SPF stage of the 2, higher protection, and a a lot decrease threat of something deactivating UV filters.
And most significantly, apply sufficient.
- 1/4 teaspoon of sunscreen in your face.
- 1 shot glass of sunscreen in your physique.
- Reapply each 2 hours.
It doesn’t matter how costly or fancy your sunscreen is, in the event you’re not making use of sufficient, you’re not getting the total SPF on the label. Interval.
The Backside Line
SPF works by limiting the quantity of UV rays that really attain your pores and skin. Layering sunscreens and merchandise with SPF received’t provide you with a better SPF. However it could provide you with higher protection.
About Gio
Hello, I am Gio. I am a no-nonsense, tell-it-like-it-is pores and skin coach and author on a mission that will help you obtain your greatest pores and skin day ever – each day. I bust skincare myths and debunk advertising and marketing jargon that will help you determine what’s definitely worth the splurge and what’s greatest left on the shelf – utilizing science, not hype. I additionally supply skincare consultations that will help you create one of the best skincare routine in your distinctive wants.
