Sunscreen Guide: Everything You Need to Know About Sunscreen

The complete guide to sunscreen

Sunscreen is a must-have in every skincare routine—it protects your skin from harmful UVA and UVB rays, reduces your risk of skin cancer, and prevents premature aging caused by sun exposure. No matter your skin type or tone, sunscreen is essential all year round.

What are the benefits of using sunscreen?

Sunscreen goes beyond shielding your skin from burns—it offers multiple benefits that contribute to long-term skin health:

Prevents sunburns. Both UVA and UVB rays can lead to skin cancers like melanoma, but UVB rays are the primary cause of sunburns. Sunscreen acts as a shield, minimizing the risk and discomfort of sunburn.
Reduces hyperpigmentation. Regular sun exposure can lead to dark spots and uneven skin tone. Daily sunscreen use—rain or shine—helps maintain a more even complexion.
Prevents DNA damage. UV rays can penetrate clouds and windows, causing DNA changes that lead to premature aging and cancer. Sunscreen protects your skin at a cellular level.

Mineral vs. chemical sunscreens: what’s the difference?

Both mineral and chemical sunscreens offer effective sun protection—but they work in different ways. Here’s what sets them apart:

Mineral sunscreen

Sits on top of the skin and creates a physical barrier
Reflects UV rays away from the skin
Can leave a white cast, especially on darker skin tones
Typically gentler and better for sensitive or acne-prone skin
More environmentally-friendly

Chemical sunscreen

Absorbs into the skin and converts UV rays into heat
Tends to be sheer, lightweight, and less noticeable on the skin
Layers well under makeup, making it ideal for everyday use
May not be suitable for very sensitive skin types

So which should you choose? Both protect your skin, but the right one for you depends on your personal preferences and skin type. If you’re looking for something gentle and don’t mind a bit of a cast, mineral sunscreen is a solid choice. If you prefer a lightweight finish that disappears into your skin, chemical sunscreen may be better suited for your routine.

Ultimately, the best sunscreen is the one you’ll enjoy wearing in a generous amount every day.

What does SPF mean?

SPF stands for Sun Protection Factor and indicates how well a sunscreen protects your skin from UVB rays, which are primarily responsible for sunburn and can contribute to skin cancer. For example, an SPF 30 sunscreen filters out about 97% of UVB rays, while SPF 50 blocks approximately 98%. While this might seem like a small increase, it’s important to understand that no sunscreen blocks 100% of UVB rays—and the jump from SPF 30 to SPF 50 isn’t double the protection, just slightly more effective for those with fair or sensitive skin, or those who spend extended time outdoors.

What’s the difference between UVA and UVB rays?

Make sure your sunscreen is labeled broad-spectrum, which means it protects against both UVA and UVB rays. UVA rays penetrate deeper into the skin and are the main culprits behind premature aging, like wrinkles and sunspots, while UVB rays affect the outer layer of the skin and cause burning. Both types can damage skin cells and increase your risk of skin cancer, so it’s essential to shield your skin from both.

When to apply sunscreen—and how much

Apply sunscreen at least 15 minutes before sun exposure to let it fully absorb and activate. Reapply every two hours—or more often if you’re swimming or sweating.

Here’s how much you need:

Face: About half a teaspoon (just the bottom of a shot glass)
Body: One full ounce (roughly one shot glass)

Don’t forget spots like ears, neck, hands, and feet—any exposed skin needs coverage.

What to look for in a sunscreen

When shopping for sunscreen, keep these tips in mind:

Match the formula to your skin type. Creams are best for dry skin, gels suit oily skin, and lightweight lotions or sprays may work well for combination types.
Choose water resistance. Even if you’re not swimming, sweat can break down sunscreen. A water-resistant formula keeps you protected longer.
Opt for a reef-safe sunscreen. Look for active ingredients like zinc oxide or titanium dioxide, which are mineral-based and less harmful to coral reefs.
Look for antioxidants. Ingredients like vitamin E add extra protection against environmental damage caused by free radicals.
Avoid a white cast. If you have a deeper skin tone, opt for a mineral sunscreen that’s tinted or a chemical formula that dries clear.
Pick a face-specific sunscreen. Facial skin is more sensitive, so choose a sunscreen formulated specifically for the face to avoid irritation or breakouts.

Does sunscreen offer complete protection?

Even the highest SPF can’t block 100% of UV rays. For full protection, combine sunscreen with protective clothing, wide-brimmed hats, sunglasses, and shade, especially during peak sunlight hours.

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