Physical sunscreen for daily use

What does physical sunscreen actually do?

Mineral filters protect skin mainly by absorbing ultraviolet radiation, rather than simply bouncing all sunlight away. They also reflect some light. Chemical sunscreen filters absorb ultraviolet radiation too, so the difference is not a choice between a physical shield and absorption. Both types can protect skin effectively. Ultraviolet radiation contributes to skin aging and skin cancer. Sunscreen reduces that exposure, but no sunscreen blocks all ultraviolet radiation. The protection depends on the finished formula and how you apply it, not just the presence of a mineral ingredient.13

What should the label say?

• SPF 30 or higher. SPF mainly describes protection against UVB, the rays primarily responsible for sunburn. SPF 30 blocks about 97% of UVB rays when applied properly.
• Broad spectrum. This means protection against UVA as well as UVB. UVA contributes to wrinkles and age spots and can pass through window glass.
• Water resistant. Check whether the label specifies 40 or 80 minutes during swimming or sweating. Water resistance does not mean waterproof.
• Mineral active ingredients. Check the Active Ingredients section rather than relying on the product name to distinguish a mineral formula from a hybrid.

Which formula suits your skin?

• Sensitive skin: Look for a sensitive skin label and avoid fragrance, parabens and oxybenzone. The sunscreen base matters as well as its active filters.
• Skin that stings with sunscreen: Choose a formula whose only active filters are zinc oxide and titanium dioxide, and avoid fragrance.
• Rosacea: Choose a sunscreen with only zinc oxide and titanium dioxide as its active filters.
• Oily or acne prone skin: Look for noncomedogenic or won't clog pores on the label. Mineral sunscreen can be a suitable option, but the mineral category alone does not settle which formula to choose.
• Dry skin: Look for moisturizing or dry skin on the label. A cream is a useful format for dry skin and facial application.
• Around the eyes: A sunscreen stick can help prevent the product dripping into your eyes. It should still meet the SPF, broad spectrum and water resistance requirements.

The best sunscreen is one you will keep using, which is a less glamorous requirement than most packaging would prefer.14

What if mineral sunscreen leaves a white cast?

Tinted sunscreens containing iron oxide also help protect against visible light, which can worsen dark spots, particularly in darker skin tones. Choose a tinted formula that still meets the sun protection requirements. Mineral sunscreens made with very small particles of zinc oxide or titanium dioxide can also spread more easily and leave less white residue.123

Is physical sunscreen better than chemical sunscreen?

Pick mineral sunscreen if sensitive skin or tolerance makes it the more practical option. If a chemical formula is easier to apply generously and use regularly, it can provide adequate protection too. For a pool day, choose by the water resistance label rather than assuming either category is automatically suitable.5

How do you apply physical sunscreen each day?

1. 1Read the bottle's directions. Application instructions can differ between creams, sticks and other formats.
2. 2Apply to dry skin 15 minutes before going outdoors. Cover skin that clothing will not protect, rather than treating sunscreen as a face only step.
3. 3Use at least 1 teaspoon for your face. Most adults need about 1 ounce to cover exposed skin across the body, with more needed depending on body size.
4. 4Cover the easy to miss areas: ears, nose, neck, hands, tops of feet, hairline and exposed scalp. Keep sunscreen out of your eyes and mouth.
5. 5Protect your lips with a broad spectrum lip balm with SPF 30 or higher.

How often should you reapply?

Reapply at least every two hours outdoors and more often after swimming or sweating, following the bottle's directions. A higher SPF does not extend the time between applications. Water resistant formulas eventually wash off too. Moisturizer or makeup with SPF still needs reapplication when you are outdoors; having SPF in another product does not remove that requirement.14

Do you need it on cloudy days or indoors?

Use sunscreen on exposed skin when going outside, including cloudy days: up to 80% of harmful ultraviolet rays can penetrate clouds. UVA can also pass through windows, so sunlight reaching your skin through glass is still relevant. A forecast UV index of 3 or higher is another clear cue to apply sunscreen. Use shade, protective clothing, a hat and sunglasses alongside sunscreen. Reflected sunlight from water, snow and sand adds exposure that deserves extra care.13

What should you expect from daily use?

Daily sunscreen helps prevent sunburn and reduces the risk of skin cancer and premature skin aging. Regular use can also reduce the risk of melasma and dark marks after inflammation. These are protective benefits, not a promise that existing wrinkles or pigmentation will disappear on a set schedule. For most people, the benefits of mineral sunscreen outweigh its risks. Keep the focus on sufficient coverage and repeat application rather than expecting a visible transformation after a few mornings.26

What if sunscreen causes a reaction?

Stop using a product that appears to trigger a rash and seek medical assessment for a persistent, painful or blistering reaction. Some sunscreen ingredients can cause an allergic reaction when combined with sunlight. Mineral sunscreen is an alternative for people with a chemical sunscreen photoallergy, but identifying and avoiding the actual trigger matters. A dermatologist can use photopatch testing to investigate an allergy that depends on light exposure. Prescription medicines, including doxycycline and some diuretics, can also cause reactions to sunlight; a rash is not automatically evidence that your sunscreen caused it.7

How do you keep sunscreen usable?

Protect the container from excessive heat and direct sunlight. Discard sunscreen after its expiration date. If there is no expiration date, replace it three years after purchase; discard it if you cannot establish its age.4