Dermatologist's Guide to Your Best Skin

Sunscreen Guide 2025: Everything You Need to Know From a Dermatologist

 

Sunscreen should be part of your daily skincare routine—but that doesn’t mean it has to be unpleasant. With summer approaching, now is the perfect time to evaluate your sunscreen strategy. The goal is to protect your skin from the sun’s ultraviolet (UV) rays, which accelerate aging and increase your risk of skin cancer. To do that, wearing sunscreen consistently is key. And consistency starts with finding a sunscreen you like. I’m here to help you do just that.

This dermatologist-backed guide breaks down how to evaluate, choose and use sunscreen as part of a comprehensive sun-safe strategy. Let’s begin with this: any sunscreen is better than no sunscreen—even amid the controversies we’ll touch on below.

What Does SPF Mean?

SPF stands for Sun Protection Factor. It measures how much solar energy (UV radiation) is required to produce sunburn on protected skin versus unprotected skin. For example, SPF 50 means it takes 50 times longer to burn with sunscreen than without—but this doesn’t account for how sunscreen degrades once applied.

SPF only measures protection from UVB rays (the ones responsible for sunburn and DNA damage). UVA rays penetrate deeper, causing wrinkles, discoloration, and contributing to skin cancer. That’s why you should look for products labeled "broad spectrum," which protect against both UVA and UVB.

Don't chase the highest SPF number. Instead, choose an SPF of at least 30, make sure it's broad spectrum, and—most importantly—reapply every two hours when outdoors.

Here’s what SPF values mean:

  • SPF 15 blocks about 93% of UVB rays
  • SPF 30 blocks about 97% of UVB rays
  • SPF 50 blocks about 98% of UVB rays

Most people don’t apply enough sunscreen to reach these protection levels. That’s another reason the American Academy of Dermatology (AAD) recommends SPF 30 or higher.

What Does PA++ Mean?

PA stands for Protection Grade of UVA, a system created in Asia to indicate UVA protection. More plus signs = better protection.

  • PA+ = 2–4 UVA-PF (50–75% protection)
  • PA++ = 4–8 UVA-PF (75–88%)
  • PA+++ = 8–16 UVA-PF (88–94%)
  • PA++++ = 16+ UVA-PF (94%+)

This system helps consumers understand UVA protection beyond just “broad spectrum.”

What About Water Resistance?

If you’re swimming or sweating, you’ll need a water-resistant sunscreen. The FDA tests and classifies products as either:

  • 40 minutes water-resistant
  • 80 minutes water-resistant

Those are the only two labels allowed. Even if a sunscreen lasts longer, "waterproof" is no longer permitted on labels. Regardless of water resistance, you must reapply regularly, especially after swimming or towel-drying.

Three General Classes of Sunscreen

Sunscreens are categorized by their active ingredients, which can be chemical, mineral (physical) or a combination of both.

Chemical Sunscreens

Active ingredients: Avobenzone, Octisalate, Octocrylene, Oxybenzone, Octinoxate.

Chemical sunscreens absorb into the skin and convert UV radiation into heat. They often feel lighter and blend in more easily, which is why they’re called cosmetically elegant. However, these ingredients may be absorbed into the bloodstream. A 2019 study in JAMA revealed that systemic levels were higher than previously thought—we still don’t know the full implications of this. The FDA is requesting more data to assess long-term safety.

Environmental concerns are also mounting. These chemicals, especially oxybenzone, are being detected in waterways and may affect ecosystems.

Mineral (Physical) Sunscreens

Active ingredients: Zinc Oxide, Titanium Dioxide.

Mineral sunscreens sit on top of the skin and physically block or scatter UV rays. They also absorb UV, but less than chemical filters. Zinc oxide offers broad spectrum protection, while titanium dioxide is better at blocking UVB.

These are Generally Recognized As Safe and Effective (GRASE) by the FDA. They're ideal for sensitive skin, pregnancy and children, and they’re more photostable than chemical filters. Downsides? They can leave a white cast and sometimes feel thicker.

Combination Sunscreens

These formulas contain both chemical and physical UV blockers. Recently, some products labeled "100% mineral" have included non-FDA-regulated chemical filters to boost SPF and improve texture.

Sunscreen Doping

Some sunscreen brands add non-regulated chemical filters to mineral formulas without clearly disclosing them. This practice—often referred to as sunscreen doping—uses chemical compounds similar to regulated UV filters, but not officially listed as active ingredients in the U.S.

Ingredients to watch for

  • Butyloctyl salicylate (similar to octisalate)
  • Ethyl ferulate (similar to octocrylene)
  • Diethylhexyl syringylidenemalonate (similar to octinoxate)
  • Tridecyl salicylate (similar to octisalate)

These ingredients may appear in sunscreens marketed as "100% mineral." If you're trying to avoid chemical UV filters, read the full ingredient list, not just the label claims.

What Do "Natural" and "Organic" Mean?

These are marketing terms, not FDA-regulated definitions.

  • Natural typically refers to mineral sunscreens with plant-based ingredients.
  • Organic means the chemical structure is carbon-based—not “clean” or “chemical-free.”
  • Non-toxic is unregulated but often associated with mineral-only formulas.

Reef-Safe Sunscreens

Reef-safe sunscreens avoid chemical UV filters, particularly oxybenzone and octinoxate, which are linked to coral bleaching and reef harm. Mineral-based sunscreens are generally considered reef-safe.

EWG Verified Sunscreens

The Environmental Working Group (EWG) rates sunscreens based on safety and transparency. Products with the EWG Verified badge:

  • Cannot be sprays or powders (to avoid inhalation risk)
  • Must have SPF between 15–50
  • Cannot use misleading claims like "sunblock," "sweatproof," or "waterproof"

How to Pick the Right Sunscreen for You

Again: the best sunscreen is the one you will actually use.

I personally choose zinc-based sunscreens for myself and my family. I recommend mineral formulas for pregnancy and sensitive skin. If you have oily or darker skin, a non-chalky chemical sunscreen may feel better and blend more easily.

My Favorite Sunscreens

Chemical Sunscreens
Combination Sunscreens
Mineral Sunscreens

What I Use

It depends on my plans.

Workday
High UV days (beach/boat)
For face on sunny/vacation days
  • SkinBetter (tinted or sheer) for long-wear, water-resistant protection.

I also use vitamin C daily, and when vacationing in sunny climates, I apply my Day Preventive Treatment with 10% vitamin C both morning and night. I pause my night treatment during these periods.

Additionally, I take oral Polypodium Leucotomos for added protection—brands I recommend include ISDIN and Heliocare.

How to Incorporate Sunscreen Into Your Daily Routine

Sunscreen is not seasonal—wear it year-round. Here’s how:

  1. Start with a vitamin C serum.
  2. Add moisturizer (if your skin is dry).
  3. Apply sunscreen—pay attention to areas most exposed to and perpendicular to the sun.
  4. Add makeup if desired.

Tips on How to use Sunscreen Properly 

  • Use 1/4 teaspoon for your face (nickel-sized amount)
  • Use 1 ounce (a shot glass) for your whole body
  • Reapply every 2 hours, or sooner if swimming, sweating or toweling off
  • Don’t rely just on makeup or powders with SPF alone—they don’t offer enough coverage or durability

Remember: sunscreen is just one piece of sun safety. Wear hats, polarized sunglasses, long-sleeve clothing and seek shade during peak hours.

You can read more about sun-safe lifestyle strategies here.

All product recommendations on this site are not sponsored and reflect the independent opinion of Dr. Heather D. Rogers, MD, based on her evidence-based research and extensive clinical experience as a practicing dermatologist. Links are provided for your convience. Some may include discounts or commissions. Please shop wherever works best for you.

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The content on doctorrogers.com and our social media channels - including articles, blogs, videos, newsletters, and linked resources - is intended for general educational purposes only. It does not constitute medical advice, establish a doctor-patient relationship, or replace consultation with your physician. Use of this information and any recommended products is at your own risk and signifies your agreement with our Terms and Conditions. Nothing shared is intended to diagnose or treat specific medical practice.

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