Sunscreen 101: do you understand sunscreen?

Sunscreen 101: do you understand sunscreen?

After all the fun facts about cleansers, moisturizers, and everything else, today we’re going to explore one of the most disliked steps in anyone’s skincare routine. Disliked because it is an unmissable component of a holistic skincare routine and because it often makes your skin feel ickier than before. Yes, I’m talking about blasted sunscreens. Love them, hate them, but cannot avoid them.


Sunscreens are a class of products that help protect the skin from UV rays. Rays produced by, the sun! UV rays can be broken into two main types, UVA and UVB. Both UVA and UVB radiation are connected to negative effects on the skin such as hyperpigmentation and photodamage but UVB owns a bigger share of the blame. The distinction between UVA and UVB is important because sunscreens come with an SPF (Sun Protection Factor) rating that is popularly used to measure their potency and efficacy. Higher SPF indicates better absorption and better protection. However, SPF rating is only an indication of the sunscreen’s efficacy against UVB rays, not UVA.

At this point, you’re probably thinking if you have exposed your skin to UVA rays all your life and if everything is doomed. The answer is, probably not. Quite often, sunscreens come with broad-spectrum and other ratings to tell you how well they protect against UVA. It’s not super straightforward to interpret these ratings but here’s a list of indicators to look for on the label:

  • Broad-spectrum: tells you that there’s some amount of protection against UVA but not necessarily how much
  • PPD: Persistent Pigment Darkening rating tells you the sunscreen’s efficacy against getting a tan. The higher the PPD, higher is the efficacy against UVA - look for one with a rating of 8 or higher
  • PA rating: also measures the amount of UVA protection and it ranges from PA+ to PA++++. Regulations and testing preferences determine whether a particular product will show a PPD or a PA rating. If it shows PA - look for PA+++ or higher

Now that we’ve covered the technical aspects of this topic, let’s get to the basics. How do you choose sunscreen and what’s a good starting point? As always, a good starting point is your current product. There are essentially three criteria that a good sunscreen needs to satisfy.

  1. Its ability to protect against UVA and UVB. Choose something with SPF 30 or higher for UVB and with PPD 8+ or PA+++ for UVA.
  2. Its feel. Sunscreen formulations do not facilitate the same light cloud-like consistencies of our beloved moisturizers. But that does not mean that it should be breaking you out. A good sunscreen is one that is comfortable to wear (sometimes it may sting when you start out but the sting should not persist) and does not leave a white cast for people of color.
  3. The third criterion can be subjective because you need to judge the product’s performance. If it’s ineffective against hyperpigmentation or if you’re noticing more freckles, then it’s time to hunt for higher rating products. If not, you’re among the people who’ve found a sunscreen that works for them - hang on to that bottle of a miracle for as long as you can.

And if you are on the hunt for a new sunscreen, remember to keep it simple. It’s possible to fall down the rabbit hole of digging into ingredients and assessing which ingredients are better but I’ve experienced that it is a fruitless discussion for actually helping you choose a product. Focus on UVA and UVB protection and irritability of the product and that’s more than enough.

One last thing to focus on is the application technique. Either apply a thick layer or two thin layers on top of each other. Make sure you don’t miss the usual suspects such as eyebrows, side of the nose, etc., reapply every four-five hours, and you are sorted! 



Meet the Writer: Iffat


Iffat is a Chicago resident trying to find a balance between enjoying the outdoors and not freezing her face. A lifelong battle with acne and an academic interest in chemistry are the driving forces behind her skincare nerdiness. She loves to talk about tennis, history, and all things skincare. She was made in Allahabad, India.