The Difference Between Sunblock and Sunscreen: What You Actually Need to Know
I’m a fervent supporter of applying and reapplying SPF regularly—which means I’m well-versed in the difference between sunblock and sunscreen. Whether I’m going for a run, lounging poolside, or just running errands on a sunny day, SPF is non-negotiable. (In case you’re wondering, SPF stands for sun protection factor.)
Protecting your skin from the sun isn’t just about avoiding painful burns or premature wrinkles—it’s one of the most important steps you can take to reduce your risk of skin cancer, safeguard your long-term skin health, and keep your complexion looking fresh and radiant.
But not all sun protection products work the same way. Some sit on top of your skin and reflect the sun, while others absorb into your skin to filter out UV rays. And understanding the difference between a physical sunscreen like sunblock and a chemical sunscreen can help you choose the best product for your skin type, lifestyle, and needs.
Below, learn the key differences between sunblock and sunscreen—including what they do, how they work, how long they last, and how to pick the right one for you.
What’s the Difference Between Sunblock and Sunscreen?
At first glance, sunblock and sunscreen may seem like interchangeable terms. Both protect your skin from the sun’s ultraviolet (UV) rays, and both are regulated by the Food and Drug Administration (FDA). But the difference lies in how they do it.
- Sunblock, also called physical sunscreen or mineral sunscreen, creates a physical barrier that ends up sitting on top of your skin and reflects the sun’s rays. It’s often made with zinc oxide or titanium dioxide and may leave a white cast on the skin.
- Sunscreen (also called chemical sunscreen) absorbs into the skin and neutralizes UV rays before they can cause damage. It’s usually lighter in texture, meaning no white cast, but can irritate sensitive skin.
This post will help you understand each type more clearly, so you can confidently choose the best sun protection for your skin and lifestyle.
What Is a Sunblock?
Sunblock is a type of physical sunscreen that forms a visible shield on the skin to physically block UVA and UVB rays. It’s typically thicker in consistency and starts working immediately after application. Because it sits on top of your skin, rather than being absorbed into it, it’s often preferred by those with sensitive skin or concerns about chemical absorption. It’s also a go-to option for kids, swimmers, and outdoor athletes thanks to its water resistance and reliable performance.
What Is the Active Ingredient in Sunblock?
Most sunblocks include one or both of these FDA-approved mineral sunscreen ingredients:
- Zinc oxide
- Titanium dioxide
One of my favorite sunblocks is the Shiseido Ultimate Sun Protector Lotion, which has an SPF of 60.
How Does Sunblock Work?
Sits on top of your skin
Sunblock forms a protective barrier that sits on top of your skin, acting like a shield.
Reflects the sun
Instead of absorbing UV rays, sunblock reflects the sun’s harmful UVA and UVB rays away from your skin.
Prevents penetration
Because it doesn’t absorb into the skin, sunblock reduces the risk of irritation and is less likely to cause breakouts or allergic reactions.
How Long Does Sunblock Last?
Sunblock generally lasts about two hours—but like all SPF products, it should be reapplied more often if you’re swimming or sweating. Look for sunblocks labeled water resistant (typically 40 or 80 minutes) and SPF 30 or higher for optimal protection.
What Is a Sunscreen?
Sunscreen is a type of chemical sunscreen that absorbs into the skin and works by converting UV rays into heat, which is then released by the body. It tends to be lighter, more transparent, and easier to apply—especially under makeup. Because it’s formulated to blend in seamlessly, it won’t leave a white cast on the skin, making it popular for all skin tones.
What Is the Active Ingredient in Sunscreen?
Sunscreens often include a mix of these chemical filters:
- Avobenzone
- Oxybenzone
- Octinoxate
- Octocrylene
- Homosalate
- Octisalate
Some of these, like oxybenzone, are controversial due to potential hormone disruption and environmental damage to coral reefs. For reef-friendly options, check out our list of best non-toxic sunscreens.
As far as chemical sunscreens go, my all-time favorite is the Supergoop! Unseen Sunscreen. It’s rather pricey at $48 for 2.5 ounces, but it’s worth every penny.
How Does Sunscreen Work?
Absorbs into the skin
Sunscreen absorbs into your skin and needs about 15-30 minutes to activate before sun exposure.
Filters and disperses UV rays
Sunscreen chemically transforms UVA and UVB rays into heat, which the body releases.
Offers sheer finish
Because it’s formulated for transparency, it won’t leave a white cast and is usually makeup-friendly.
How Long Does Sunscreen Last?
Sunscreen should also be reapplied every two hours, especially if you’re in direct sunlight, swimming or sweating, or towel drying. Look for formulas that are SPF 30 or higher and labeled water resistant for better coverage throughout the day.
Which Is Better: Sunscreen or Sunblock?
Both sunscreen and sunblock have pros and cons. Your ideal choice depends on your skin type, lifestyle, and values:
- Sensitive skin? Go for sunblock—zinc oxide or titanium dioxide tend to be gentler and less likely to clog pores.
- Worried about the finish? Sunscreen offers a sheer finish that blends better with makeup and doesn’t leave a white cast on the skin.
- Doing water sports or hiking? Choose a water-resistant sunblock that stays put during swimming or sweating.
- Concerned about reef safety or chemical absorption? Stick to reef-safe mineral sunscreen.
Regardless of what you choose, you should reapply every two hours, wear a hat and sunglasses, and use sunscreen year-round—not just in the summer. The sun shines all year, after all. Need help layering SPF with your daily glam? Check out our guide on how to reapply sunscreen with makeup.
Understanding the difference between sunblock and sunscreen isn’t just helpful—it’s essential to protecting your skin from the sun. Whether you prefer the mineral protection of sunblock or the blendable ease of sunscreen, what matters most is that you use it consistently, correctly, and in tandem with other sun-safe practices. So go ahead—protect your skin, avoid burns, and stay glowing all summer long.
