Sunscreen After Forty

Sunscreen is, for most adults, the single most effective thing you can do for the long-term appearance and health of your skin. The advice does not change after forty; if anything, it matters more, because cumulative exposure is what shows.

The number

Use a broad-spectrum SPF 30 or higher. SPF 30 blocks roughly 97 percent of UVB; SPF 50 blocks about 98 percent. No sunscreen blocks everything, and the difference between 50 and 100 is marginal. What matters is application.

The amount

Most people apply about a quarter of what they need. A nickel-sized dollop for the face; a shot glass full for the body. Reapply every two hours of sun exposure, and after swimming or heavy sweating.

The everyday

Sunscreen belongs in the morning routine, every morning, year-round — including winter and overcast days. UVA, which drives most ageing, penetrates cloud and glass. The morning commute through a windshield is real exposure.

The formulation

Modern formulations have moved well past the thick white paste of a generation ago. Mineral sunscreens (zinc oxide, titanium dioxide) sit on the surface and are well tolerated by sensitive skin. Chemical filters absorb UV and tend to be lighter and invisible. Either is fine; the best sunscreen is the one you'll actually wear daily.

What sunscreen cannot do

It cannot reverse existing damage. It cannot replace a hat, shade, and sensible hours out of the midday sun. And it is not a reason to extend your time in the sun — the goal is protection, not permission.

This article offers general information. For concerns about spots, moles, or changes in your skin, see a doctor or dermatologist.