How to Choose a Sunscreen: The Best and Worst Sunscreen Ingredients for Your Skin

Is your SPF as safe and effective as it should be?
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Sunscreen ingredients

According to the Environmental Working Group's latest report, 75 percent of the sunscreens currently on the market offer inferior protection or contain worrisome ingredients.

That means most brands are selling sunscreens that don't actually meet the protection claims on their labels—leaving you vulnerable to sunburn, premature aging and even skin cancer. (Can you believe it?) 

What's more, active ingredients that absorb into the bloodstream and cause hormone disruption are still in widespread use.

No wonder I get so many questions about how to choose a safe, effective SPF!

In this tutorial, I'm walking you through my EXACT process for evaluating sunscreen ingredients. You will learn: 

  • Why you should only use insoluble sunscreen filters
  • The minimum SPF number you need (and how to calculate it)
  • How to ensure you're protected from both UVA and UVB rays
  • Which inactive ingredients to minimize or avoid

I've also got a free checklist for you to download at the end of this article!

How to Check Sunscreen Ingredients

1. Does It Contain Only Insoluble Sunscreen Filters?

Sunscreen ingredients

Kinship Self Reflect Probiotic Moisturizing Sunscreen SPF 32

The first thing you need to do is determine whether your sunscreen's active ingredients are soluble or insoluble.

  • Soluble sunscreen filters penetrate your skin (due to their small particle sizes) and absorb into your body. 
  • Insoluble sunscreen filters do not penetrate your skin (due to their large particle sizes) and therefore cannot absorb into your body.

"This is our first precept of safety," explains Dr. Sharyn Laughlin, medical director of Laserderm and co-founder of The Sunscreen Company. "Filters that are large in molecular weight and are insoluble do not penetrate skin and achieve blood and tissue levels, bind to brain receptors, cross the placenta to the fetus, and enter breastmilk."

By avoiding soluble filters, you also avoid exposing yourself to potential hormone disruption. 

"A 2016 review of 85 scientific papers in humans and lower species concluded that [soluble] hydrocarbon UV filters are generally involved in the disruption of the hypothalamic–pituitary–gonadal system," Dr. Laughlin told Dermatology Times. "More recent studies in 2018 and 2019 confirm that [they] clearly change levels of virtually every sex hormone, pituitary hormones, thyroid hormones and certain growth factors in both pregnant and non-pregnant women."

So which active ingredients should you look for? The best insoluble filters include:

  • Tinosorb A2B (tris-biphenyl triazine)
  • Tinosorb M (bisoctrizole or methylene bis-benzotriazolyl tetramethylbutylphenol)
  • Tinosorb S (bemotrizinol or bis-ethylhexyloxyphenol methoxyphenyl triazine)
  • Titanium dioxide
  • Zinc oxide

Of these, only titanium dioxide and zinc oxide are approved by the FDA for sale in the US. In Canada, all are approved by Health Canada except for Tinosorb A2B; however, Tinosorb M and Tinosorb S are only allowed in low concentrations compared to other jurisdictions. 

So here in North America, zinc oxide and titanium dioxide are our best options. 

They also happen to be the ONLY two filters the FDA classifies as Generally Regarded as Safe or Effective (GRASE). (Meanwhile, 12 soluble filters—cinoxate, dioxybenzone, ensulizole, homosalate, meradimate, octinoxate, octisalate, octocrylene, padimate O, sulisobenzone, oxybenzone and avobenzone—were all recently delisted, so they no longer have that designation.)

Note: Although they, too, are insoluble, I haven't included Mexoryl SX (ecamsule or terephthalylidene dicamphor sulfonic acid) and Mexoryl XL (drometrizole trisiloxane) on the above list. As L'Oréal patented ingredients, they can only be found in combination with the undesirable soluble filters.

2. Is It SPF 30 or Higher?

Sunscreen ingredients

REN Clean Screen Mineral SPF 30 Mattifying Face Sunscreen

Once you've established that your sunscreen contains only insoluble filters, your next step is to calculate its SPF. 

According to Dr. Laughlin, we all need to be using at least an SPF 30 for broad-spectrum protection.

The problem is, you can't trust that the SPF numbers claimed on labels are truly accurate. 

Dr. Denis Dudley, a former OB-GYN and endocrinologist and the co-founder of The Sunscreen Company, refers to a landmark study presented at the 2017 meeting of The Photomedicine Society. Looking at 50 commercially available sunscreens labelled as SPF 50 or higher, the researchers found they were in fact only SPF 6 to 10 when measured in sunlight.

This happens because of several flaws in the way SPF numbers are measured. For example, a higher number can be achieved simply by adding anti-inflammatory ingredients that reduce redness.

But if you know your sunscreen's concentration of active ingredients, you can estimate its SPF number on your own.

Here's how it works. For every one percent of each active ingredient, you get a certain amount of SPF units:

Sunscreen FilterMaximum SPF Units Per 1%

Tinosorb A2B

SPF 2.0

Tinosorb M

SPF 2.2

Tinosorb S

SPF 3.1

Titanium dioxide

SPF 2.6

Zinc oxide

SPF 1.6

So let's say you have a formula with 20 percent zinc oxide. Since every one percent of zinc oxide gives you 1.6 SPF units, that works out to SPF 32—an ideal level of protection.

3. Does It Provide High UVA Protection?

Sunscreen ingredients

EleVen by Venus On-the-Defense Sunscreen SPF 30

Now that you've chosen an SPF 30 (or higher) sunscreen that uses soluble filters, you need to make sure it's giving you enough UVA protection.

As explained in my UVA vs UVB tutorial,

  • UVA (the aging rays) are the main trigger for skin cancers and photo-aging.
  • UVB (the burning rays) are the main trigger for sunburn.

Most sunscreens on the market are what Dr. Laughlin calls "UVB-biased." In other words, they do a good job of filtering out the UVB rays that cause burns, but are inadequate against the more damaging UVA rays. This is especially troubling because UVA accounts for 94 percent of the UV light that reaches our skin!

Fortunately, all but one of the soluble filters on our list give extensive UVA protection:

Sunscreen FilterUVAUVB

Tinosorb A2B

⚫ Extensive protection

⚫ Extensive protection

Tinosorb M

⚫ Extensive protection

⚫ Extensive protection

Tinosorb S

⚫ Extensive protection

◐ Partial protection

Titanium dioxide

◐ Partial protection

⚫ Extensive protection

Zinc oxide

⚫ Extensive protection

⚫ Extensive protection

As you can see, titanium dioxide is the only one with limited UVA-filtering ability, which is why it should always be combined with a stronger UVA filter, such as zinc oxide.

4. Does It Contain at Least 15% Zinc Oxide?

Sunscreen ingredients

Love Sun Body Mineral Sunscreen SPF 30

Now, are there certain minimum percentages of active ingredients that you need to look for? 

Yes! "For the North American consumer, it comes down to zinc oxide at a concentration of at least 15 percent as the best filter to protect against UVA," says Dr. Laughlin.

That means you've got two options for getting to an SPF 30:

  • 20-25% zinc oxide: Since it gives you extensive protection against both UVA and UVB, zinc oxide alone can be the sole active ingredient in your formula. Look for a concentration of at least 20 percent up to a maximum of 25 percent. (Remember that every one percent of zinc oxide is equivalent to 1.6 SPF units, so 20 percent is SPF 32, while 25 percent is SPF 40.)
  • 15-20% zinc oxide + >5% titanium dioxide: Alternatively, you can combine zinc oxide with titanium dioxide to get broad-spectrum UVA and UVB protection. To go with your minimum 15 percent zinc oxide, Dr. Dudley recommends looking for at least five percent of titanium dioxide. (Since every one percent of titanium dioxide equals 2.6 SPF units, this works out to approximately SPF 37.)

5. Is It Low in PUFAs?

Sunscreen ingredients

Juice Beauty SPF 30 Oil-Free Moisturizer

With all skincare products—not just sunscreen—I recommending limiting or avoiding polyunsaturated fatty acids (PUFAs).

PUFAs are volatile, unstable fatty acids that are highly susceptible to oxidation in the presence of heat and light. (And in a sunscreen, you're getting lots of both!)

When PUFAs oxidize, they become rancid and generate free radicals, which are a major cause of skin aging and cellular damage.

Here's the PUFA content of some of the most common oils found in skincare products:

Oil% PUFAs

Almond oil

17.4%

Cocoa butter

3.0%

Coconut oil

1.8%

Corn oil

58.7%

Grape seed oil 

69.9%

Olive oil

8.4%

Safflower oil

74.5%

Sesame oil

41.7%

Shea butter

6.6%

Sunflower oil

40.1%

Personally, I try to avoid any oils that are more than about 15 to 20 percent polyunsaturated.

When this isn't possible, I at least make sure they're not present in high concentrations. As a general rule, I look at the five ingredients, which typically represent about 80 percent of a product.

If you're not sure whether an oil is polyunsaturated, you can always Google "[oil name] fatty acid profile" to find out.

Otherwise, an easy way to avoid PUFAs is to choose an oil-free sunscreen, such as Juice Beauty SPF 30 Oil-Free Moisturizer.

6. Is It Low in Fragrance? (Optional)

Sunscreen ingredients

Drunk Elephant Umbra Tinte Physical Daily Defense SPF 30

Since fragrance ingredients are the number one trigger for irritations from personal care products, your skin will be happiest if you limit them, if not avoid them completely.

These includes not just synthetic fragrance but also essential oils, which can be equally irritating:

  • Citronellol
  • Essential oils (citrus, rose, etc.)
  • Fragrance
  • Geraniol
  • Limonene
  • Linalool
  • Parfum
  • Perfume

When choosing a sunscreen, go for either fragrance-free formulas or products that list fragrance at the end of their ingredients lists. Sephora's Clean Beauty Seal is also helpful, because it lets you know that the product has less than one percent synthetic fragrance.

7. Is It Low in Silicone? (Optional)

Sunscreen ingredients

Derma E Sun Defense Mineral Oil-Free Sunscreen SPF 30 Face and Derma E Sun Defense Mineral Sunscreen SPF 30 Body

To be clear, silicones have no bearing on sunscreen safety. But since they may affect the condition of your skin, you might consider limiting or avoiding them, too.

Silicones give products "slip" and create a smooth, silky finish by forming a film on top of your skin surface.

But this film may interfere with your skin's ability to conduct its natural renewal processes, including sloughing off dead skin cells.

It can also lock debris and other comedogenic ingredients into your pores, which can lead to clogging and breakouts.

Here are some of the most common silicones you'll see on ingredients lists:

  • Cyclohexasiloxane
  • Cyclopentasiloxane
  • Dimethicone
  • Methicone
  • Triethoxycaprylylsilane
  • Trimethicone

Just like PUFA oils, when I can't avoid silicones completely, I at least make sure they're not listed in the first five ingredients of a product.

The Best Sunscreens to Try

EleVen by Venus On-the-Defense Sunscreen SPF 30

EleVen by Venus On-the-Defense Sunscreen SPF 30

EleVen by Venus On-the-Defense Sunscreen SPF 30

EleVen by Venus On-the-Defense Sunscreen SPF 30 contains the highest possible concentration of zinc oxide, 25 percent, in a silicone-free and fragrance-free lotion that is invisible on ALL skin tones.

REN Clean Screen Mineral SPF 30 Mattifying Face Sunscreen

REN Clean Screen Mineral SPF 30 Mattifying Face Sunscreen

REN Clean Screen Mineral SPF 30 Mattifying Face Sunscreen

REN Clean Screen Mineral SPF 30 Mattifying Face Sunscreen is a mattifying, silicone-free sunscreen with 22 percent zinc oxide and rice starch to absorb excess oil.

Kinship Self Reflect Probiotic Moisturizing Sunscreen SPF 32

Kinship Self Reflect Probiotic Moisturizing Sunscreen SPF 32

Kinship Self Reflect Probiotic Moisturizing Sunscreen SPF 32

Kinship Self Reflect Probiotic Moisturizing Sunscreen SPF 32 protects with 22.4 percent zinc oxide while it blurs pores (sans silicone) and gives skin a subtle glow.

Juice Beauty SPF 30 Oil-Free Moisturizer

Juice Beauty SPF 30 Oil-Free Moisturizer

Juice Beauty SPF 30 Oil-Free Moisturizer

Juice Beauty SPF 30 Oil-Free Moisturizer gives you 20 percent zinc oxide along with oil-free, silicone-free hydration and a dewy finish.

Drunk Elephant Umbra Tinte Physical Daily Defense SPF 30

Drunk Elephant Umbra Tinte Physical Daily Defense SPF 30

Drunk Elephant Umbra Tinte Physical Daily Defense SPF 30

Drunk Elephant Umbra Tinte Physical Daily Defense SPF 30 has a sheer tint, 20 percent zinc oxide and no silicones, fragrance or essential oils. 

Derma E Sun Defense Mineral Oil-Free Sunscreen SPF 30 Face

Derma E Sun Defense Mineral Oil-Free Sunscreen SPF 30 Face

Derma E Sun Defense Mineral Oil-Free Sunscreen SPF 30 Face

Derma E Sun Defense Mineral Oil-Free Sunscreen SPF 30 Face contains 20 percent zinc oxide in a non-greasy, oil-free and silicone-free cream.

Love Sun Body Mineral Sunscreen SPF 30 

Love Sun Body Mineral Sunscreen SPF 30

Love Sun Body Mineral Sunscreen SPF 30

Love Sun Body Mineral Sunscreen SPF 30 is ideal for your body, protecting it with all-natural ingredients including 20.4 percent zinc oxide.

Check out these guides for even more sunscreen recommendations:

Conclusion + Free Checklist

Now you have all the information you need on the best and worst sunscreen ingredients for your skin!

It's a lot to remember—which is why I created the How to Choose a Sunscreen Checklist. Just click below to download it so you have a handy reference when checking your sunscreen ingredients lists. (It's FREE!)

How to Choose a Sunscreen Download

I hope I've made it clear that choosing a safe, effective SPF is not as simple as just grabbing a product labelled "natural" or "mineral." 

Reading the ingredients list is key to ensure you're getting a TRUE broad-spectrum SPF 30—and protection against not only sunburn but also skin cancer and skin aging!

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