How do you know which sunscreen to use?

What should you look for on the label?

• Broad spectrum means protection against both UVA and UVB, the two types of harmful ultraviolet rays that reach your skin.
• SPF 30 or higher is the minimum to look for. SPF describes protection against UVB, which causes sunburn.
• Water resistant means protection lasts for a stated period on wet or sweaty skin. Look for 40 or 80 minutes.
• On UK labels, look for at least four UVA stars. A UVA circle also indicates that the product meets the EU standard.
• Check the expiry information. An open jar symbol with a number and M tells you how many months the sunscreen lasts after opening.

These protection features matter more than the format: suitable sunscreen helps prevent sunburn, reduces skin cancer risk and helps prevent early skin aging. Protection depends on how you apply sunscreen as well as what you buy. A bottle with the right label is the starting point, not the whole job.1

Should you choose SPF 30 or SPF 50?

SPF 30 provides about 97% protection against UVB; SPF 50+ provides about 98% when enough is applied. Choose the higher number if you want greater protection, but keep the same application and reapplication habits. Neither blocks all UV radiation. SPF is based on testing with a defined amount of sunscreen, so spreading a small amount over a large area reduces the protection you receive.24

Does mineral or chemical matter?

Mineral sunscreens use zinc oxide, titanium dioxide or both; chemical sunscreens use other UV filters. Both protect mainly by absorbing UV radiation, rather than mineral sunscreen acting only as a reflective shield. Mineral formulas are a useful starting point for sensitive skin. The deciding label features remain broad spectrum protection, sufficient SPF and water resistance. Check the active ingredients rather than relying only on the product name.24

Which texture suits your skin?

Visible light can worsen dark spots, particularly in darker skin tones; tinted sunscreens containing iron oxide help protect against it. A matching tint can also reduce white residue, so the finish does not have to announce the application. For sprays, spray until skin glistens, then rub in for even coverage. Never spray near the face or mouth, into the wind, near heat or an open flame, or while smoking.2

Do you need an expensive sunscreen?

Less expensive sunscreens with the same ingredients work as well as expensive ones. Choose by protection features and whether the formula suits regular use. Buy insect repellent separately: sunscreen needs frequent reapplication, while repellent should be applied less often.5

How do you apply enough sunscreen?

1. 1Apply generously before going outside, following the product's directions. For an outing long enough to risk burning, apply about 30 minutes before leaving and again just before going out.
2. 2Use around six to eight teaspoons if covering your entire adult body. Applying sunscreen too thinly reduces protection.
3. 3Cover all exposed skin, including the face, neck, ears and head if hair is thinning or absent. A wide brimmed hat is better for protecting the head.
4. 4Reapply every two hours outdoors and follow the manufacturer's directions. Reapply straight after being in water, after towel drying or sweating, and when sunscreen has rubbed off.

The second application helps cover patches missed the first time. Pay particular attention to the ears, back of the neck and exposed scalp if a wide brimmed hat is not covering them. During exercise or sweaty garden work, reapply more regularly because sunscreen can be sweated off or wiped away. Clothing and shade should be your first line of protection, with sunscreen covering the remaining exposed skin.6

Is water resistant sunscreen enough for swimming?

Choose water resistance for swimming or sweating, but read the stated duration. The 40 or 80 minute claim describes tested protection during swimming or sweating, not permission to skip reapplication. No sunscreen is waterproof: all eventually wash off. Follow the label's instructions for reapplying after water exposure, and do not wait beyond two hours outdoors.7

Makeup and moisturizers carrying broad spectrum SPF claims are also regulated as sunscreen products in the US. The protection claim still comes with sunscreen directions; the cosmetic format does not remove the need for reapplication. Check those directions before deciding that your usual makeup application can serve as your sun protection.7

When do you need sunscreen?

Use sunscreen when going outdoors, including short outings and in winter. Clouds are not a reason to leave sun protection behind. The UV index measures UV intensity; daily sunscreen is recommended when it is forecast to reach three or higher. UVA can pass through clouds and windows. Shade, clothing and sunglasses remain part of protection rather than extras reserved for a beach trip.45

What should you choose for children?

For toddlers and children, zinc oxide or titanium dioxide formulas are useful options because they contain fewer chemicals that can irritate young skin. Keep children covered with clothing, hats and sunglasses, and out of the sun during peak hours. For babies younger than six months, prioritize shade and clothing and speak to a pediatrician before using sunscreen.5

If you are buying sunscreen for travel, check local ingredient restrictions before packing. Some destinations restrict particular chemical filters because of concerns about coral reefs, and mineral sunscreens are generally preferred in those locations. Rules differ by destination, so check the current local requirements rather than assuming one formula is accepted everywhere.4

If you burn, stay out of the sun until redness has gone. Seek medical help if you feel unwell or your skin swells badly or blisters. Sunscreen is not a reason to extend time in the sun.3