How to choose broad spectrum sunscreen for daily use

What should the label say?

SPF measures protection against sunburn, which is caused mainly by UVB rays. Broad spectrum adds the requirement for protection against both UVA and UVB, so a large SPF number alone is not enough to make your choice. Look for both the number and the words. In the United States, a sunscreen must pass a broad spectrum test to carry that label.4

A familiar brand name is not one of the three essentials, however much room it takes up on the bottle. Brand recognition matters less than broad spectrum protection, using enough sunscreen and applying it regularly.5

What does daily sunscreen do?

Regular sunscreen use helps prevent sunburn, reduces skin cancer risk and helps prevent early signs of skin aging. The purpose is protection from further sun exposure, not a visible transformation after a set number of days. UVA contributes more to premature aging and remains intense throughout daylight hours; UVB is most intense around midday. Protecting against only one leaves part of the problem unaddressed.36

How do you apply it each day?

1. 1Apply generously 15 minutes before sun exposure. Use the directions on your sunscreen for any additional product instructions.
2. 2Cover all exposed skin, rather than only your face. Include exposed ears and the back of your neck, and get help reaching your back.
3. 3Use enough for the area you are covering. An adult body application takes about one ounce, roughly a shot glass worth; that is not a face only amount.
4. 4If you use a spray, rub it in to spread the coverage. Missed patches are easy to leave with a spray.
5. 5Reapply every two hours while outdoors. Apply again after swimming, sweating or toweling off, and follow the label's water resistance interval.

Water resistance is temporary, not permission to leave one application on through a day of swimming. Check whether the bottle says 40 or 80 minutes. Not all sunscreens are water resistant, and the duration matters when your skin gets wet or sweaty.3

Do you need sunscreen on cloudy or winter days?

Clouds and cool air do not remove UV exposure. Check your local UV index, which describes the strength of the sun's ultraviolet rays, and protect exposed skin when the index is 3 or higher. The amount of UV you receive also depends on how long you spend outside. A brief outing and a long afternoon outdoors are not the same exposure.12

At a UV index of 0 to 2, risk is generally low, but bright snow changes the calculation. Fresh white snow can reflect more than 80% of UV rays. On bright, snowy days, cover up and use sunscreen if you will be outside for more than an hour. Higher elevations increase exposure too, making mountain skiing a different proposition from a winter walk without snow.1

Which sunscreen suits your skin?

Tinted sunscreen also helps protect against visible light, which can worsen dark spots. Keep the same SPF, broad spectrum and water resistance requirements. Around the eyes, a sunscreen stick can help prevent sunscreen from dripping into them; the stick still needs all three essentials.7

What is the difference between broad spectrum and mineral sunscreen?

Broad spectrum describes the rays a sunscreen protects against; mineral describes its sunscreen ingredients, such as zinc oxide and titanium dioxide. These are different questions, despite sharing a bottle that already has plenty to say. A mineral sunscreen still needs a broad spectrum label and SPF 30 or higher. Mineral options can be less irritating and are worth considering for sensitive skin.35

When should you change sunscreen or get medical advice?

If sunscreen stings or burns, switch to a fragrance free option using only zinc oxide and titanium dioxide as sunscreen ingredients. Stop use and ask a doctor if a rash occurs. Do not apply sunscreen to damaged or broken skin, and keep it out of your eyes. If it gets into your eyes, rinse with water.47

Some medicines increase sensitivity to sunlight, including doxycycline, retinoids and certain anti inflammatory medicines. If you take a medicine that increases sun sensitivity, discuss sun protection with your clinician rather than relying on sunscreen alone. Extensive blistering after sun exposure needs medical care because severe burns can require fluid replacement and pain control.6

For babies younger than six months, prioritize shade and protective clothing and ask a doctor before using sunscreen. For children aged six months or older, choose sunscreen made for children; many contain zinc oxide and titanium dioxide.47

Check the bottle and protect more than your skin

Check the expiration date. Sunscreen without an expiration date has a shelf life of no more than three years, and high temperatures shorten its shelf life. An old bottle exposed to heat is not something to keep relying on.2

Combine sunscreen with shade, clothing that covers your skin, a hat with a brim all the way around and sunglasses that block UVA and UVB. A baseball cap leaves the ears and back of the neck exposed, so cover those areas or apply sunscreen. Shade reduces exposure, but sunscreen and protective clothing still belong in the plan.2