Sunscreen vs. Sunblock: What’s the Difference?

SPF use is universally recommended by dermatologists to shield your skin from sun damage. Yet when it comes to sunscreen vs. sunblock, while both product types provide protection, there are some key differences that may make one more suitable for your skin and lifestyle. 

However, it’s worth knowing that you likely won’t see “sunblock” on the shelves at the store. Since 2011, the U.S. Food and Drug Administration (FDA) has banned manufacturers from using the term sunblock in an attempt to reduce consumer confusion. 

That’s why “it’s more useful to classify sunscreens based on the ingredients they’re made from,” says Victoria Billero, MD, FAAD, a clinical dermatologist at Tufts Medical Center. “Dermatologists classify sunscreens as ‘chemical’ or ‘mineral’ sunscreens,” she says—while colloquially, mineral sunscreen may called sunblock. 

Below, our experts explain the benefits and drawbacks of sunscreen vs. sunblock—as well as how to use SPF sun protection effectively for long-term skin health. 

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Sunscreen vs. sunblock: What’s the difference?

Molly Donovan, PharmD, RPh, MBA, an ambulatory care pharmacist at Cleveland Clinic, explains that both sunscreens and sunblocks protect the skin from the sun’s damaging rays: 

• UVB rays that cause the skin to burn 
• UVA rays, which are responsible for aging

But the products work in slightly different ways. 

Sunscreen

“Chemical sunscreens act by absorbing and then scattering UV sun rays, so these protect through a completely different mechanism than mineral sunblocks,” Dr. Massick explains. Basically, sunscreen absorbs the rays into the chemicals so that they are not absorbed by the skin, says Dr. Donovan.

“The chemical ingredients in sunscreens cover specific UVA and UVB ranges, so a combination or mixture of chemical ingredients—usually three to four—are required to provide broad-spectrum coverage,” says Dr. Massick.

As long as the product is a “broad-spectrum” formulation—meaning it protects against both UVA and UVB rays—and it’s used properly, both sunblock and sunscreen will protect your skin from sun damage, including sunburn, sun poisoning, early signs of aging, and skin cancer.

Sunblock

“Sunblock uses a physical barrier of cream to reflect, or block, the sun’s rays away from the skin,” Dr. Donovan says.

This cream is made from natural mineral ingredients that don’t get absorbed into your skin or the bloodstream, explains Susan Massick, MD, a dermatologist at The Ohio State University Wexner Medical Center. 

Sunscreen vs. sunblock: Active ingredients

While both sunscreen and sunblock protect your skin from the sun’s harsh rays, they use different chemicals to do so. Before applying a product to your skin, learn what’s often found in each of them.

Active ingredients in sunscreen

Dr. Donovan says that chemical sunscreen formulations most commonly contain the following six ingredients. Here’s what they are and what they do:

• Avobenzone is very effective at protecting the skin against UVA rays. On its own, it’s unstable and loses efficacy quickly, so it’s usually combined with more stabilizing chemicals, such as octocrylene.
• Octocrylene absorbs both UVB and UVA rays, acts as a stabilizer for ingredients like avobenzone, and promotes water resistance.
• Octisalate forms a protective film on the skin, which protects it from UVB rays, and is considered to have a good safety profile, according to the National Institutes of Health (NIH).
• Homosalate protects against UVB rays and acts as a stabilizer to help prevent other chemicals from losing their protective strength.
• Ecamsule is a highly effective UVA ray filter that’s known for its excellent photostability, per the NIH.
• Oxybenzone is a highly effective sun-protective chemical that absorbs both UVB and UVA rays.

Are sunscreen chemicals safe?

The FDA uses a classification system called “GRASE,” or “generally recognized as safe and effective.” Dr. Billero says, “The FDA currently considers chemical sunscreens as GRASE, though they are requesting more data into certain ingredients—including avobenzone, octinoxate, and oxybenzone—to see if they can continue to be classified as GRASE.”

Notably, oxybenzone and octinoxate are losing favor in the medical community and starting to be phased out of sunscreen formulations, Dr. Massick says. This is largely due to concerns over their hormone-disrupting potential, which means it might interfere with how the body’s hormones work. Studies are still ongoing, but 2023 research published in Applied Sciences states that given the current data, oxybenzone should be prohibited.

Active sunblock ingredients

Sunblock—or mineral sunscreen—is a much simpler formulation. “Sunblock is most commonly zinc oxide (think: diaper cream) or titanium dioxide,” Dr. Donovan explains. “It is not absorbed into the skin, but instead works as a physical barrier on top.”

Are sunblock ingredients safe?

Both zinc oxide and titanium dioxide are rated GRASE by the FDA for use in sunscreens.

According to 2023 research published in StatPearls:

• Zinc oxide is very stable and effective at protecting against UVA rays; it shields the skin from UVB rays as well, but not as effectively as titanium dioxide.
• Titanium dioxide offers broad-spectrum protection from UVB rays but only protects against some UVA rays.

Sunblock products that combine zinc oxide and titanium dioxide are most effective for shielding your skin from the sun. “These sunscreens will provide broad-spectrum coverage with both UVA and UVB protection,” says Dr. Massick.

Sunscreen vs. sunblock: Application

“Sunblock is a cream that is applied, sits on top of the skin, and works immediately after application,” Dr. Donovan says. “Sunscreen needs at least 20 minutes of time after application to absorb into the skin for it to work best.”

The key to safe application for either product is to apply liberally and uniformly on your skin, Dr. Massick says. “You can’t really put on too much sunscreen or sunblock, but you can make the mistake of not using enough,” she says. “Uneven application, missed spots, and ignored areas can result in sunburns—pay special attention to ears, lips, back of the neck, feet, and scalp.” 

Sunscreens come in different forms, too. “All should still be rubbed in when applied,” Dr. Massick says. The experts say there are a few other things to consider based on product type.

Sunscreen lotions

“Lotions are applied by hand, allowing for control of application and a more even coverage,” Dr. Donovan says. “It is good for all skin types and easy to apply, but can feel heavier on the skin and is not as convenient for large areas or a quick application.” 

Sunscreen sprays

“Sprays are quick and easy to apply, good for large areas and hard-to-reach places, and feel lighter on the skin, but it is hard to control the amount applied and, due to propellants used in the bottles, are not ideal for people with sensitive skin,” Dr. Donovan says. “They also need to be applied in well-ventilated areas because it can be irritating to the lungs if inhaled.” Some sprays can be flammable, too. 

You do need to rub in sunscreen sprays for full effectiveness as well. “Otherwise, you’ll end up with skipped or missed spots,” Dr. Massick says. “You can spray the aerosol in your hand and then apply to avoid zigzag tan stripes or losing product to the wind when applying outdoors.”

Sunscreen sticks

“Sticks are best for targeted and mess-free application to the face, nose, and ears, and they are much more portable,” Dr. Donovan says. “But [sunscreen sticks] are not convenient for large areas and do not allow for as quick of an application.” 

Dr. Massick says to consider using stick applicators for areas like the forehead to minimize stinging if sunscreen runs into your eyes—and on the lips for the ease of application. 

How often to apply sunscreen or sunblock

Dr. Massick urges the importance of reapplying sunblock or sunscreen at least every two hours, especially if you’re out in the sun and heat or if you’re sweating or swimming. “Water-resistant sunscreens may only last 40 to 80 minutes, so it’s important to reapply [more often.]” 

If you’re indoors, it’s still recommended to wear and reapply sunscreen at least every four to six hours, as the sun’s rays can still make their way through windows, Dr. Donovan says. 

ADragan/Getty Images

Possible side effects

“The most common side effects of both sunblock or sunscreen are skin irritation, redness, itching, rash, and in some cases, allergic reaction,” Dr. Donovan says. If irritation occurs, changing to a different kind (sunblock instead of sunscreen) may help.

Another common side effect: if sunscreen or sunblock is not used correctly or not reapplied thoroughly and often enough, you can still get a sunburn, she adds. 

Side effects of chemical sunscreens

“These chemicals can be irritating to people with sensitive skin, can clog pores and make acne worse, and have also been linked to affecting hormone levels in the body, specifically estrogen,” Dr. Donovan says. Though she says that hormonal disruption is a less common risk—and more research is needed to determine the extent of this potential issue. 

“Some people can develop allergies to certain organic filters used in chemical sunscreens and develop rashes upon use,” adds Dr. Billero. “Some of the more common allergens are avobenzone and oxybenzone.” 

Because chemical sunscreens can be absorbed into the bloodstream, the ingredients can enter breast milk. “It’s recommended that pregnant or breastfeeding women avoid chemical sunscreens and opt for mineral sunscreens instead,” Dr. Billero says. 

There are also concerns that some of the chemicals in these sunscreens can harm marine life, especially coral reefs. “However, the data is still inconclusive,” she says. Still, Hawaii banned chemical sunscreens containing oxybenzone and octinoxate in 2021. 

Side effects of sunblocks 

“Because there is no absorption, mineral sunblocks don’t typically cause rashes or skin irritation in a way that chemical sunscreens potentially can,” Dr. Massick explains. But if you have sensitive skin, avoid products with added fragrance, says Dr. Donovan. 

Mineral sunblocks can also be harder to apply, and “some people do not like the white cast they leave behind,” Dr. Billero says. As they can easily rub off, mineral sunscreen may also need to be reapplied more frequently. However, many newer products are formulated to make application easier and reduce the appearance of a white cast. 

Uwe Krejci/Getty Images

Sunscreen vs. sunblock: Which is better?

Chemical sunscreen and mineral sunblocks each have their advantages, says Dr. Billero. “There are also hybrid sunscreens that contain both chemicals and minerals.” 

The benefits of chemical sunscreens include:

• They’re usually more lightweight and disappear completely when blended into the skin, often making them easier to use, ensuring full coverage.
• They also don’t leave a thick layer or white cast, which people may not like the look and feel of.
• They are generally more water-resistant and don’t rub off as easily as mineral sunscreens. 

The benefits of mineral sunscreens (sunblock) include:

• “[They’re] less likely than chemical sunscreens to cause allergic reactions and irritation, so they are preferable for people with sensitive or more eczema-prone skin,” Dr. Billero says.
• They’re less likely to cause or exacerbate acne.
• The minerals are not absorbed into the bloodstream, so they’re often regarded as safer than chemical sunscreens—which are still being studied for potential effects on human health. 

However, that’s only if you use the product properly. Some mineral-based products don’t blend onto the skin easily (and can leave a white cast when you use the appropriate amount for protective coverage), and most require more frequent application. 

Still, the main takeaway from our experts is that any form of SPF sun protection is key to preventing sun damage and reducing your skin cancer risk. Both mineral and chemical-based sunscreens are considered safe and effective, and the best product is the one that you’ll use consistently. “Don’t be afraid to try different products until you find the right one for you,” Dr. Donovan says. 

What to look for in a sunscreen or sunblock

When shopping for sunscreen or sunblock, look for:

• A broad-spectrum formula
• Water resistance
• SPF 30+ for daily use and SPF 50+ for prolonged outdoor exposure

There are also a few more things to keep in mind if you want to keep your skin in tip-top shape. For example, if you’re swimming, chemical sunscreen tends to be more water-resistant than mineral sunblock. And take note: “There’s no such thing as ‘towel-proof’ or ‘sweat-proof’ sun protection,” Dr. Donovan says.

For people with acne-prone skin, mineral sunscreen poses less risk for breakouts. But if you prefer a chemical sunscreen formulation, look for products that are oil-free and labeled “non-comedogenic,” which means it’s designed with ingredients that won’t clog your pores.

“If someone is concerned about hyperpigmentation, tinted mineral sunscreens are best,” Dr. Billero adds. “The tinted sunscreens contain iron oxide, which blocks visible light. Visible light contributes to hyperpigmentation.”

Whichever type of sunscreen you choose, Dr. Massick emphasizes using a product that’s easy to apply so that you’ll actually use it consistently.

Further tips for sun protection

“Not all sun protection is limited to sunscreen,” Dr. Massick says. “Make use of hats, sunglasses, and UPF (Ultraviolet Protection Factor) swimsuits, rash guards, and clothing.” 

Other tips for sun protection from the experts:

• Seek shade when possible, especially when the sun’s rays are the strongest—usually between 10 a.m. and 4 p.m. 
• Try to avoid full sun exposure when the day’s UV index (a measure of the strength of the sun’s rays) is high—you can check this through many weather apps. 
• Wear sunscreen when indoors or in the car, as UV rays can go through windows.
• Use tinted mineral sunscreen on areas prone to hyperpigmentation like the face or neck.
• Opt for chemical sunscreen if you need water-resistant sun protection.
• Buy new sunscreen every year. “Please discard last year’s half-used bottle,” Dr. Massick says.
• Use sunscreen daily, even in winter or on cloudy or rainy days. 
• Sun protection is important for people with darker complexions, too. ”Everybody can get a sunburn and ultimately skin damage,” Dr. Donovan says. 

“For the boaters, surfers, skiers, and snowboarders, water and snow reflect the sun’s rays and can increase the risk for burns, so make sure to reapply your sunscreen often,” Dr. Billero adds. 

There is also a plant extract called Polypodium leucotomos, which is available as an oral capsule. “This can reduce the risk of burning and is helpful if taken prior to prolonged outdoor activities, such as a long run, a round of golf, or fishing,” says Dr. Billero. “Of course, this should not be used in place of sunscreen but in addition to sunscreen and sun protective behaviors.” 

For daily wellness updates, subscribe to The Healthy by Reader’s Digest newsletter and follow The Healthy on Facebook and Instagram. Keep reading:

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• You and Your Child Should Never, Ever Use the Same Sunscreen—Here’s Why
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• 11 Signs Your Sunburn Is Actually Sun Poisoning, According to Expert Dermatologists