First of all, it’s easy for a skincare blogger or a “skinfluencer” to say you need to wear sunscreen all the time. As a “skinfluencer” (and a pale white one at that) I have access to a lot of sunscreens that work for me, don’t irritate my skin, and don’t leave a white cast. For me, it makes sense to wear sunscreen every day, even if I’m indoors, because I can and because I want to test them out to share my thoughts with you all.
The Real Cost of Sunscreen
But in reality, for many people, wearing sunscreen every day isn’t so simple. It can be hard to find a sunscreen that works for you. And let’s be honest, sunscreen can be expensive! Especially if you’re applying the recommended amount and reapplying throughout the day. In order to get the SPF on the label, you need to apply 2 mg/cm^2. This translates to about 1/4 teaspoon just for your face, or 1/2 teaspoon for your face and neck. If you are using just a 1/4 teaspoon of sunscreen, a 50 ml bottle of sunscreen would last you about 40 days with one application daily, about 20 days with two applications daily, and about 14 days with three applications daily. Considering that a 50 ml facial sunscreen bottle usually costs $10 to $40… that really adds up. Imagine you have a $40 sunscreen and you’re applying 1/4 teaspoon three times a day. That means you would be spending over $1000 a year on sunscreen, just for your face. If you apply 1/2 teaspoon, it’s over $2000.
Now, I don’t want to scare you away. Sunscreen is still important and there are more affordable options out there. I just want to emphasize how sunscreen can be inaccessible to many. And there are reasons why people may not want to or be able to use it daily, especially when they are indoors. But in no way do I mean to discount the importance of sunscreen.
What the Research Shows
So let’s get down to it. Most dermatologists do recommend wearing sunscreen daily, even when indoors. Windows block UVB (which causes burning) but not all UVA rays (which cause photoaging). If you are near a window, you are still getting exposed to UVA. Thus, especially if photoaging (think wrinkles, sun spots, etc.) is a concern for you, it’s best to wear sunscreen indoors. Fortunately, you are pretty well protected from UVB rays, which are a main factor in the development of some skin cancers.
Okay, so it’s good to apply sunscreen indoors to protect against UVA rays. But what about reapplying? Well, a 2018 study in Thailand put this to the test. This was a small study that was certainly limited, but the results are still interesting to consider. During this trial, 20 indoor workers applied 2 mg/cm^2 of sunscreen to their faces, which was mixed with an invisible blue fluorescent agent. Their faces were photographed at the time of application and then every 2 hours afterward. These photographs were then analyzed afterward using a digital image analysis software. This trial showed that the amount of sunscreen present on the workers’ faces decreased by an average of 16.3% after two hours and then decreased minimally after that. By the end of the 8 hour day, 71.8% of the sunscreen was still present on their faces. If you are interested in reading more about this study, Kind of Stephen has a great explanation on his blog.
If these results are accurate, I think it’s pretty impressive that about 70% of the sunscreen remained after 8 hours. The biggest dip did occur after the first 2 hours, so if you really are concerned with getting maximum protection, it probably is best to reapply every 2 hours. However, if 70% protection is okay with you, then just a single application could be effective.
My Personal Conclusions
So…. what’s the verdict? Do I need to wear sunscreen indoors?
Well, it’s ultimately up to you and will depend on your priorities. But, if it’s accessible to you, I would recommend wearing sunscreen indoors for greater protection. And if you use ingredients such as retinoids or AHAs that make your skin more photosensitive, I think it’s even more important.
As far as reapplication goes, personally, I do not usually reapply throughout the day unless I’m sweating or going outside. I feel comfortable knowing that some remains on my face even if my exposure is slightly increased throughout the day. I also don’t have a lot of windows in my apartment, so that may be another factor that you would want to keep in mind. However, if you really want to get the maximum UVA protection while you’re indoors, you should probably reapply every 2 hours.
“Affordable Sunscreens”
It is a good idea to apply sunscreen at least once a day even if your inddors. But, as I mentioned above, the cost of sunscreen can really add up. Even if you choose a less expensive sunscreen, say $10, and you only apply 1/4 teaspoon once a day, that’s still about $100 a year. I personally think that seems like quite a lot just for sunscreen for your face. Considering how important sunscreen is, there really should be even more affordable options out there.
Anyway, here are some of the most affordable sunscreens I could find. I haven’t tried all of these, but I will be trying out more soon so I can share reviews with you all!
Skin Aqua UV Tone Up Essence SPF 50+ PA++++
- $12.99 for 80 ml ($0.16 per ml)
A’Pieu Pure Block Sun Crean SPF 45 PA+++
- $14.40 for 100 ml ($0.14 per ml)
Etude House Mild Watery Light SPF 50+ PA+++
- $9.90 for 50 ml ($0.20 per ml)
Black Girl Sunscreen Kids SPF 50
- $9.99 for 89 ml ($0.11 per ml)
- $13.90 for 140 ml ($0.10 per ml)
Missha All-Around Safe Block Aqua Sun Gel SPF 45 PA++++
- $8.99 for 50 ml ($0.18 per ml)
Make p:rem UV Defense Me. Blue Ray Sun Fluid SPF50+ PA++++
- $30.32 for 200 ml ($0.15 per ml)
Australian Gold Botanical Tinted Face Sunscreen Lotion SPF 50
- $13.99 for 89 ml ($0.16 per ml)
Sources/Additional Reading:
https://labmuffin.com/spf-changes-how-much-sunscreen-use/
https://www.keckmedicine.org/myth-or-fact-you-dont-need-sunscreen-if-you-are-indoors-all-day/
https://kindofstephen.com/sunscreen-office-indoors/
https://pubmed.ncbi.nlm.nih.gov/30273065/
Disclaimer: This Site contains both non-affiliate and affiliate links, and I may receive an affiliate commission for any purchases made by you on the affiliate website using such links. Some products marked by (*) were gifted to me for review purposes, but all thoughts are my own honest opinions. I am not an expert, these are just my personal experiences, and what works for me might not work for you.
