Sunscreen is the single most evidence-backed anti-ageing product you can buy, and one of the most misunderstood. The big number on the front — SPF — is genuinely useful, but it only tells you about one type of UV. Get the full picture and you'll choose better and waste less money.
SPF is only half the label
SPF measures protection against UVB — the rays mainly responsible for sunburn. It says nothing, by itself, about UVA — the deeper-penetrating rays associated with long-term skin ageing and damage. A high SPF with poor UVA protection is only doing half the job.
How to read UVA protection on a UK label
This is the bit people miss. On UK and EU sunscreens, look for:
- The "UVA" in a circle — this logo means the product meets the EU recommendation that UVA protection is at least a third of the SPF. It's the quickest signal to look for.
- PA ratings (PA+ to PA++++) — common on Asian and some imported sunscreens; more plus signs means more UVA protection.
- Star ratings — Boots' UVA star system (up to five stars) rates UVA protection relative to UVB. More stars is better.
"Broad spectrum" is the phrase that tells you a product covers both UVA and UVB. If you see it alongside the UVA-in-a-circle logo, you're covered on the protection that matters.
How much you apply beats the number
Here's the truth that saves you money: most people under-apply sunscreen dramatically, which is why real-world protection falls far short of the label. The tested amount is about 2mg per cm² — roughly two fingers' length of product for the face and neck.
SPF30 applied properly outperforms SPF50 applied thinly. Generosity beats the number.
So a well-applied, broad-spectrum SPF30 is plenty for everyday use, and reapplying matters more than chasing SPF100. Spend on a texture you like enough to use generously and top up.
Mineral vs chemical
Both work. Mineral (zinc oxide, titanium dioxide) sits on the skin and suits sensitive or reactive types, though it can leave a slight cast. Chemical filters absorb UV and tend to feel lighter and more invisible. Neither is "safer" or "better" in general — choose the one that feels good enough that you'll actually wear it every day.
A broad-spectrum SPF30+ with clear UVA protection, in a texture you'll reapply
Check for the UVA-in-a-circle logo (or good PA/star rating), then pick on feel. For daily use, a pleasant SPF30 you apply generously beats a heavy SPF50 you skimp on. You don't need to overspend — high-street own-brand and mid-range sunscreens routinely meet the same standards as pricier ones.
FAQ
Is SPF50 a waste of money?
Not at all — it's a sensible margin of safety given most people under-apply. Just don't assume it lets you skimp on quantity or skip reapplying.
Do I need sunscreen in the UK in winter?
UVA is present year-round and through cloud and glass. Daily facial SPF still makes sense, especially if you use actives like retinol.
Does makeup with SPF count?
Rarely enough on its own — you'd need far more than anyone applies. Treat it as a bonus on top of a dedicated sunscreen, not a replacement.