☀ The Science

PA++++ Explained: The Rating Your Sunscreen Probably Doesn't Have

You know SPF. But do you know PA++++? It's the UVA protection rating used across Asia — and it measures protection against the rays that cause ageing, pigmentation, and long-term skin damage. Most Western sunscreens use a different system. The best Korean ones have it at maximum.

When most people think about sun damage, they think about burning. Redness, peeling, the uncomfortable aftermath of too long on the beach. That's UVB radiation — and SPF (Sun Protection Factor) measures how well a sunscreen blocks it.

But there's another type of UV radiation that receives far less attention: UVA. These longer wavelength rays don't cause burning. You don't feel them. They penetrate deeper into the skin and cause damage that accumulates silently over years — collagen breakdown, dark spots, uneven skin tone, fine lines, and the loss of firmness that we associate with aged skin.

What SPF Doesn't Tell You

SPF only measures UVB protection. On its own, the number tells you nothing about UVA. That's why you need a second rating to know how well a sunscreen protects against the type of sun damage that shows up on your face at 40.

In the US, "broad spectrum" labelling just tells you some UVA protection is present, not how much. In the UK and EU, the UVA circle logo means UVA protection is at least a third of the SPF, and some brands add a star rating on top. The PA system gives a more granular reading at a glance.

The uncomfortable truth: a high SPF number doesn't guarantee high UVA protection. You could be faithfully applying SPF every day and still be under-protected against UVA-related skin ageing if you're not checking the UVA rating too.

The PA System — Japan and Korea's Solution

Japan developed the PA (Protection Grade of UVA) rating system and it's been widely adopted across Asia, including Korea. It gives consumers a clear, tiered indication of UVA protection:

PA+ · Some UVA
PA++ · Moderate
PA+++ · High
PA++++ · Maximum

PA++++ is the highest possible rating. It indicates that the sunscreen provides maximum protection against UVA radiation as measured by the persistent pigment darkening (PPD) method. A product must achieve a PPD value of 16 or higher to earn PA++++.

Why PA++++ Changes Everything

When you see PA++++ on a sunscreen, it tells you the formula has been designed and tested for comprehensive broad-spectrum protection — not just the UVB coverage that keeps you from burning, but the UVA coverage that prevents your skin from ageing prematurely.

Paired with SPF 50+, PA++++ means you're getting the full picture of sun protection. Both the acute damage (burning) and the chronic damage (ageing) are covered. It's the difference between a sunscreen that protects you today and one that protects your skin over a lifetime.

UVA Rays Come Through Windows

Here's the detail that changes behaviour for most people who learn it: UVA rays penetrate glass. UVB rays — the burning rays — are largely blocked by windows. UVA rays are not.

If you sit near a window at work, commute in a car, or spend time in rooms with natural light — you are receiving UVA exposure. Every day. Regardless of the weather. The person who drives to work every morning and sits by a window for eight hours is accumulating UVA exposure on the side of their face nearest the window, year after year.

This is precisely why Korean skincare culture insists on daily SPF even in winter, even indoors, even on overcast days. And it's why PA++++ — not just SPF — is the mark of a serious sunscreen.

UVB (what SPF measures) UVA (what PA measures)
Causes sunburn Causes skin ageing
Blocked by glass Penetrates glass
Strongest in summer Present year-round
Felt immediately Damage accumulates silently
Blocked by SPF 50 Requires PA++++ for max defence

What to Look For

The simple rule: you want both. SPF 50+ for UVB and PA++++ for UVA. That combination gives you complete sun protection — the kind that dermatologists in Korea have been recommending as a daily non-negotiable for decades.

Most Korean sunscreens display both ratings clearly on the packaging. In the UK, check for the UVA circle logo alongside the SPF. Either way, the point is the same: look at both numbers, not just one.

SPF 50+ PA++++. Both. Always.

One recommendation. Maximum protection. The formula Korea has trusted for years.

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