What PA++++ Actually Means (& Why Your SPF Is Only Half the Story)

If you watched my video on this, you already got the quick version. But I want to go a little deeper here because this is one of those things that once you understand it, you can’t unsee it on every sunscreen label. And honestly, it changed how I shop for SPF entirely.

So we all know SPF, right? I wrote a whole post about it (if you haven’t read it, go do that first— Sun Protection Factor, AMEN). But here’s the thing most people don’t realize: SPF only measures your sunscreen’s ability to block UVB rays. That’s it. Just the B’s.

UVB rays are the ones that primarily affect the outermost layers of your skin— they’re responsible for tanning, sunburns, and that surface-level redness you get after a long day outside. Important? Absolutely. But that’s only half of what’s hitting your skin.

SPF vs. PA — Two Different Jobs Here’s the thing most people don’t realize: SPF and PA are measuring two completely different things. They’re not redundant— they’re partners. And you need both. Let me break down what each one is actually protecting you from. Measured by SPF UVB Rays Shorter wavelength rays that primarily affect the outermost layers of the skin. These are the ones you can feel: Sunburn Surface-level redness Tanning Skin cancer risk at the surface Measured by PA UVA Rays Longer wavelength rays that penetrate much deeper into the skin— down to where your collagen and elastin live: Hyperpigmentation & dark spots Collagen breakdown & wrinkles Loss of elasticity Deeper skin cancer risk The Long Game: Why UVA Rays Are Sneaky

This is where the PA rating comes in. PA stands for Protection Grade of UVA, and it measures how well your sunscreen blocks UVA rays— which are a completely different beast. UVA rays have a longer wavelength, meaning they penetrate much deeper into the skin. We’re talking past the surface, down into the layers where your collagen and elastin live. These are the rays responsible for things like hyperpigmentation, wrinkles, loss of firmness, and yes— skin cancer. The sneaky part? You can’t feel them. There’s no burn, no redness, no immediate sign that damage is happening. It’s all happening underneath, quietly, over time. And here’s something that really got me when I first learned it: UVA rays are present at nearly the same intensity all year round. They penetrate hroughclouds.They penetrate through glass— your car windows, your office windows. You could be sitting inside feeling perfectly comfortable and UVA is still reaching your skin. That’s why I’m so adamant about daily SPF even when you’re “not really going outside.” SPF blocks what burns you. PA blocks what ages you. Your sunscreen needs to address both. What the Plus Signs Actually Mean The PA rating system originated in Japan and you’ll see it a lot on Asian beauty sunscreens (which, side note, tend to be some of the best formulated sunscreens out there). The + signs indicate the level of UVA protection you’re getting. More plus signs = stronger protection. Simple as that. PA+ Some Protection Minimal UVA defense. I wouldn’t rely on this for daily use. PA++ Moderate A decent baseline. This is the minimum I’d recommend. PA+++ High Protection Great for daily use, especially if you’re managing pigmentation. PA++++ Highest Protection Maximum UVA coverage. This is what I look for personally. When you’re shopping for sunscreen, you’ll want to look for PA++ and higher for moderate protection. If you’re someone who’s actively using retinoids, dealing with hyperpigmentation, or you just want to be thorough about anti-aging— aim for PA+++ or PA++++. What to Look For on the Label Not every bottle will show the plus signs. In the US, the FDA uses “Broad Spectrum” labeling instead of the PA system. So if your sunscreen says Broad Spectrum, that means it does include UVA protection— they just don’t break it down into the plus sign scale the way Asian sunscreens do. Look for both Broad Spectrum + SPF 30 or higher as your baseline and you’re in good shape. So what should I actually look for on the label? The ideal combo: SPF 30–50 (or higher) + PA+++ or PA++++ if it’s listed, OR the words “Broad Spectrum” if it’s a US product. Either way, you want a sunscreen that’s addressing both UVB (the burn) and UVA (the aging). One without the other isn’t doing the full job. I think the reason a lot of people overlook this is because we were taught to just look at the SPF number. Higher number = better, right? Not exactly. SPF 30 blocks about 97% of UVB rays. SPF 50 blocks about 98%. The difference in protection is actually pretty small— what matters more is that you’re applying it consistently and that you have UVA coverage too. That’s the piece most people are missing. Why this matters if you’re treating your skin If you’re using Vitamin C in the morning (which I recommend to every client), pairing it with a sunscreen that covers both UVA and UVB is one of the most protective things you can do. Vitamin C neutralizes free radicals while your SPF blocks the rays causing them. It’s a team effort. And if you’re on a retinoid at night— which increases your skin’s sensitivity— having strong UVA protection during the day is even more important. You’re doing all this work to renew your skin at night, the last thing you want is UVA undoing it during the day. Treating hyperpigmentation without blocking UVA is honestly like mopping the floor while the faucet’s still running. You can keep mopping but until you turn it off, the problem isn’t going away. Common Questions I Hear Do I need sunscreen even if I’m indoors? Yes— especially if you’re near windows. UVA penetrates glass, so sitting by a window at home or in the car means you’re still getting exposure. I know it feels excessive but it makes a real difference over time. Is a higher SPF number always better? Not necessarily. The jump from SPF 30 to 50 is about 1% more UVB protection. What matters way more is consistent application and making sure you have that UVA coverage too. Don’t get caught up in the numbers game. Why doesn’t my sunscreen list a PA rating? The PA system is widely used in Asia but the US uses “Broad Spectrum” as the UVA indicator instead. If your sunscreen says Broad Spectrum, it’s providing UVA protection— they just label it differently. Look for both Broad Spectrum and SPF 30+ as your baseline and you’re covered. Does sunscreen expire? It does. Most sunscreens have a shelf life of about 2–3 years and the active ingredients do break down. If you’ve had the bottle longer than you can remember, it’s probably time for a new one. The Bottom Line I hope this clears up some of the confusion around those little plus signs. Once you know what to look for, it becomes second nature to check the label. And if nothing else, just remember: SPF protects against the burn, PA protects against the deeper damage— the wrinkles, the dark spots, the stuff that shows up years later and you can’t figure out where it came from. You need both. Every day. If you have any questions, send me a DM or leave a comment. Always happy to help you figure out what works for your skin. Thank you for reading and being here :) -Rache