UVA vs UVB: The Different Types of UV Rays—and Why You Need to Protect Your Skin From Both, Year-Round

Your sunscreen might not be doing its job.
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The Skincare Edit and Ava Isa

We all know UV rays harm our skin—but if you think the average sunscreen gives you proper protection, think again.

Although there are two types of ultraviolet radiation that cause sun damage, most SPFs only do a good job of defending against one of them. 

That means they still leave you vulnerable to the most prevalent and dangerous form of UV, which is the main culprit behind skin cancers and premature aging.

Shocked? Me too—which is why I reached out to Dr. Sharyn Laughlin to find out more, and what we can do to be protected.

Dr. Laughlin is a board-certified dermatologist, the medical director of Laserderm, and the co-founder of The Sunscreen Company. As you know, I've been a fan of their CyberDerm sunscreens for years, and now I've fallen in love with their newest sunscreen line, Ava Isa (which just launched at Credo Beauty!).

In this tutorial, you will learn:

  • The difference between UVA and UVB rays, and what they do to your skin
  • Why you need to wear sun protection year-round (even in winter)
  • The reason most sunscreens don't actually protect against UVA (despite claiming to be "broad-spectrum") 
  • How to choose a truly broad-spectrum sunscreen—and why Ava Isa is one of your best bets!

What is Ultraviolet Radiation?

Electromagnetic spectrum

The electromagnetic spectrum.

Ultraviolet radiation, or UV radiation, is a form of invisible electromagnetic energy that comes from sunlight. It can also be produced by man-made sources such as black lights and tanning beds (although you should definitely steer clear of the latter!). There are three wavelengths of UV radiation: 

  • UVA is long-wave radiation between 320 and 400 nanometers (nm)
  • UVB is short-wave radiation between 280 and 320 nm
  • UVC is intensive short-wave radiation between 100 and 280 nm

Fortunately, we don't need to worry about UVC, since it's filtered out by the ozone layer and never reaches the earth's surface—or our skin. But that's not the case for UVA and UVB, which do affect our skin in different ways. Here's how.

UVB, the Burning Rays

If you've ever had a sunburn, then you know the symptoms of too much UVB exposure. 

"UVB rays are the shorter wave rays in the UV spectrum, and initiate early sunburn," says Dr. Laughlin. "They are Nature's warning signal to tell people to get out of the sun." 

However, a sunburn isn't just uncomfortable. It also causes DNA mutations that, when combined with UVA exposure, play a role in skin cancer.

UVA, the Aging Rays

While UVB acts on the epidermis, the uppermost layer of our skin, that's not the case for UVA. It also penetrates more deeply, to the dermis, where it ultimately causes more damage.

"UVA rays are the longer wave rays that do the most harm," says Dr. Laughlin. "UVA accounts for 94 percent of the UV light that reaches our skin, and according to studies from the past two decades, is the main driver of skin cancer and photo-aging."

That's because UVA suppresses the immune system and interferes with DNA repair, which encourages the formation of wrinkles and pigmentation as well as melanoma and other skin cancers.

Why You Need UV Protection Year-Round

Sunscreen is the only way to protect your skin from UVA and UVB, and believe it or not, it's just as important in the winter as it is in the summer.

"UVA is ubiquitous and constant all year round and does not vary according to latitude or time of day," says Dr. Laughlin. "So everyone should wear sunscreen at any time of day, in any season, in any location on the planet."

In other words, even if you avoid the sun between the so-called peak hours of 10 a.m. and 2 p.m., it only reduces your risk of burning, but has little effect on preventing skin cancer and photo-aging. Staying inside or in your car doesn't mean you're safe, either, because we're exposed to UV through windows and windshields. 

So there's no getting around it—you need to apply sunscreen every day, first thing in the morning, regardless of your intended activity. But not just any sunscreen....

Why Most Sunscreens Don’t Protect Against UVA

UVA Protection Factor of Leading Sunscreens

The UVA Protection Factor of the leading sunscreens on the market, compared to CyberDerm and Ava Isa from The Sunscreen Company.

Sunscreens are usually labelled "broad-spectrum," meaning they claim to protect you from both UVA and UVB rays. Unfortunately, most are failing when it comes to UVA.

In the sunscreen industry, there are several on-skin and computer tests that companies use to calculate measurements such as SPF, Critical Wavelength and the UVA-Protection Factor (UVA-PF). According to Dr. Laughlin, a TRULY broad-spectrum sunscreen should be SPF 30 or higher, with a UVA-PF of at least 10 to 20. 

The problem is, the US Food and Drug Administration and Health Canada don't require UVA-PF testing—even though it's the best way to determine how well a sunscreen defends against UVA radiation. Instead, they allow manufacturers to infer the level of UVA protection (and therefore make the claim "broad-spectrum") based on another, far less accurate test. 

As a result, 90 percent of sunscreens on the market only achieve a UVA-PF of 5 to 8, which is way too low. And without high UVA protection, they have little if any chance of preventing the development of skin cancer or premature skin aging, says Dr. Laughlin. 

That's not the only issue with these UVB-biased sunscreens. Recently, the FDA delisted 12 active ingredients (cinoxate, dioxybenzone, ensulizole, homosalate, meradimate, octinoxate, octisalate, octocrylene, padimate O, sulisobenzone, oxybenzone and avobenzone), so now they are NOT Generally Recognized As Safe and Effective (GRASE). 

"They are potential hormone disruptors and DNA mutagens and should be avoided," explains Dr. Laughlin. "The entire group has been shown to enter blood at different rates to attain peak levels, and every one is bioavailable to a fetus and to all of us. They also happen to be among the leading causes of photo-contact allergy and are implicated in marine degradation."

How to Choose a Truly Broad-Spectrum Sunscreen


Choose a sunscreen with insoluble filters and high UVA protection.

So how do you go about choosing a sunscreen, when so many of them aren't doing their jobs properly—and even causing harm? According to Dr. Laughlin, these are the two most important criteria:

  • Insoluble filters: "This is our first precept of safety. Filters should not be absorbed into the body." Insoluble filters are active sunscreen ingredients that have a high molecular weight and will not penetrate the skin, enter blood or tissue, bind to brain receptors, cross the placenta to the fetus, or enter breastmilk. 
  • High UVA protection: For true broad-spectrum protection, the filters must also have high UVA-PF values. "Fortunately, the same filters that meet the first precept also include the best UVA filters."

Zinc oxide, Tinosorb M, Tinosorb S and Tinosorb A2B are the four active sunscreen ingredients that get Dr. Laughlin's seal of approval. But currently, none of the Tinosorb filters are approved in the US, and in Canada, Tinosorb M and Tinosorb S are only allowed in low quantities. 

"Therefore, 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." That's where Ava Isa comes in!

Introducing Ava Isa Sunscreen


Ava Isa Aurora Rose Ultra Matte SPF 45 Sunscreen and Ava Isa Pure Untinted Ultra Matte SPF 45 Sunscreen.

Ava Isa is a new line of sunscreens that Dr. Laughlin and her team developed to meet the needs of young people in particular. 

"Melanoma is now the leading cause of cancer deaths of 15- to 30-year-old women in North America, and other forms of skin cancer have doubled on average in North America over the last 60 years," she explains. After her granddaughter Ava Isabella was born, Ava Isa was created with the goal of "encouraging young people to get in the habit of using a truly protective sunscreen as early on as possible."

As such, the Ava Isa SPFs not only deliver high UVA and UVB protection, but they're also so lightweight, they don't even feel like sunscreen! Here's why the formula is such a game-changer:

  • High in zinc oxide: Ava Isa sunscreens are made with 15 percent zinc oxide in combination with a patent-pending, certified organic material called Bio UVA Ultra. The latter "improves the dispersion of zinc oxide and makes it more efficient, says Dr. Laughlin, "so our 15 percent zinc oxide is equivalent to a 25 percent concentration or higher."
  • Superior UVA protection: You're also getting SPF 45 protection, with a high UVA-PF of 14.95. In comparison, nearly all other mineral sunscreens have a UVA-PF of only 10 to 12. Ava Isa gives you almost 50 percent more UVA protection than even the leading mineral sunscreen options on the market.
  • Lightweight and matte: Sunscreens, especially mineral sunscreens, have long had a bad reputation for feeling heavy, occlusive and greasy. That's not the case with Ava Isa—"you can now have an all-mineral sunscreen with a high concentration of zinc oxide that is incredibly lightweight, ultra-matte and dries down on the skin almost instantaneously."
  • Transparent on most skin: Ava Isa is available with and without a tint, and once blended, becomes imperceptible on most skin tones, says Dr. Laughlin. Pure Untinted is the untinted version, while Aurora Rose has a rose-gold tint with subtle iridescence. However, if you have a darker skin tone (V or VI on the Fitzpatrick scale), you may prefer formulas without titanium dioxide, since it can impart a greyish tone. Try CyberDerm Every Morning Sun Whip SPF 30.
  • Clean and silicone-free: "The beauty industry is really moving away from silicones and other controversial ingredients," says Dr. Laughlin. "We've found ways of formulating mineral sunscreens using alternative emollients that spread quickly and allow us to create aesthetically pleasing, fluid textures."
  • Fragrance-free: "As a dermatologist, I try to promote products that are fragrance-free, whether the fragrances comes from synthetic chemicals or essential oils. Synthetic fragrances can contain a cocktail of chemicals that can be sensitizing. Essential oils, although naturally derived, can also be sensitizing and sometimes photo-toxic. Therefore, all of our products, including Ava Isa, are fragrance-free."
  • Suitable for all skin types: Ava Isa sunscreens are ideal for anyone who hates the greasy feel of traditional sunscreens, especially those with oily, combination or acne-prone skin. But you can also wear them even if you're on the drier side—just use them after a good moisturizing routine.

How to Apply Ava Isa Sunscreen


Swatches of Ava Isa Pure Untinted Ultra Matte SPF 45 Sunscreen and Ava Isa Aurora Rose Ultra Matte SPF 45 Sunscreen.

"Ava Isa will blend to be transparent, but there are some tricks for best application," says Dr. Laughlin. "You do need to apply it with a little bit of care, but the payoff is that it becomes imperceptible once applied and blended." Here's what she recommends:

  1. Cleanse and moisturize: Sunscreen should always be the last step of your skincare routine, before makeup. So use Ava Isa on clean skin, after hydrating with a serum and/or moisturizer. 
  2. Shake the tube well: Shaking before each use will ensure the ingredients and pigment are evenly dispersed.
  3. Use a quarter-sized amount: This should be enough for your face, neck, chest and hands (but use more if any other areas will be exposed to the sun). Squeeze the sunscreen onto the back of your hand and warm it up with your fingertips.
  4. Apply in sections: Since this sunscreen is very fast-drying, you need to work quickly in sections. For example, you could apply it to your face, one quadrant at a time, rubbing it into your skin as you go. Blend the edges as you would any colour cosmetic, avoiding your eyebrows and hairline.
  5. Re-apply if necessary: If you're going to have extensive sun exposure throughout the day, definitely re-apply Ava Isa. But if you're only getting incidental exposure, like your daily commute, then one application is probably sufficient and more practical.


Now you know the difference between UVA and UVB, and the best way to protect your skin year-round.

The bottom line? "The most important reason to use a sunscreen with high UVA protection is to prevent skin cancer over your lifetime," says Dr. Laughlin. "But I find that people are sometimes more motivated by preserving the look of their skin than statistics relating to skin cancer." 

"In my clinic, patients sometimes invest thousands of dollars into improving their skin with laser treatments and injectables, but I always tell them their investment goes out the window if they do not preserve it with a high UVA sunscreen," she explains. "Studies have shown that the daily use of a truly broad-spectrum sunscreen over a lifetime can shave up to 20 years off the look of your skin."

Where to Buy + What’s Next

You can find Ava Isa sunscreens at:

And keep an eye out for some exciting new products launching in 2020! Ava Isa Sun-é-Serum SPF 35 will be a fluid serum sunscreen with antioxidant benefits that filters out UVA, UVB and blue light. Ava Isa Sun Lip Sun Whips will be mineral sunscreen lip balms in brightly coloured tints (as well as untinted). Make sure to follow The Sunscreen Company on Instagram and Facebook for updates!

Have you tried Ava Isa sunscreen yet?
What did you think?

In Partnership with Ava Isa

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