Sunscreen Explained: What It Is & Why You Need It (and my top picks!)

Just how important is sunscreen? When I look at the many different products on my shelves, there are a few that I consider absolutely essential to my routine. Cleansers are of course necessary. Moisturizers definitely, and I wouldn’t go without any serums. But if asked which product would I ABSOLUTELY need to take with me to a desert island? Sunscreen, hands down.

I used to be one of those people who was obsessed with tanning. I fried myself to a crisp on the beach one too many times, and definitely did not treat my skin with care. But when I worked as a ski instructor, the combination of wind and burn I experienced convinced me how critical it was that I wore sunscreen every single day. Now, I don’t go without it – and I stress to my friends just how important it is too. Even if you’re just getting into skincare, sunscreen is one of the three products you must have in your routine.

sunscreen flatlay

What exactly is sunscreen?

Sunscreen is a lotion, spray, gel, foam, stick or other topical product that absorbs or reflects some of the sun’s ultraviolet radiation. This helps avoid sunburn, as well as some other nasty long-term effects we’ll get into later.

What does the SPF stand for?

According to wikipedia, the sun protection factor (SPF rating, introduced in 1974) is a measure of the fraction of sunburn-producing UV rays that reach the skin. For example, “SPF 15” means that ​115 of the burning radiation will reach the skin, assuming sunscreen is applied evenly at a thick dosage of 2 milligrams per square centimeter.

What will happen if you don’t wear sunscreen?

The immediate effects of not wearing sunscreen are well known to all of us: hot, red, painful skin. After a week at the beach, we might have some peeling or blisters. Sunburns suck, but they aren’t the only danger posed by not wearing sunscreen.

Not using sunscreen can also speed up the rate of aging, contributing to wrinkles, dark spots and loss of elasticity. But in addition to looking old, the sun can also have much more dangerous impacts.

Any sunburn increases your risk of developing skin cancer, but you don’t have to turn your skin lobster red to be at risk of cancer. Any sun exposure without protection (sunscreen, clothing, shade) makes it more likely you will be diagnosed with skin cancer at some point in your life. Getting that tan really isn’t worth it.

Wait, isn’t sunscreen bad for me?

There has been some concern that certain ingredients in sunscreens may be absorbed into the bloodstream. However, not enough research has been done. We don’t know how much is absorbed, and if that quantity is harmful. At this point, what we do know is that the risks of skin cancer are much more concrete and real than the potential risks posed by the chemicals contained in the formulas.

If these risks make you inclined to avoid sunscreen, you can make the simple switch to mineral sunscreens (some of which I’ll discuss later in my recommendations). These formulas use physical blockers, rather than chemicals, to reflect and absorb the sun’s light. While it does make them more difficult to work into the skin (in some formulas), it negates the potential, as yet unproven risk potentially posed by chemical sunscreens.

Is sunscreen bad for the environment?

There has been more substantive research done about whether sunscreen has a negative impact on our environment, particularly with our oceans. If you are vacationing on the beach and want to be environmentally conscious, there are a number of reef-safe sunscreens that you can choose from.

How does sunscreen work?

According to the Yale Scientific, sunscreen works by blocking and absorbing UV rays through a combination of physical and chemical particles. Physical particles like zinc oxide and titanium dioxide reflect UV radiation from the skin. Chemical ingredients, if the sunscreen is not strictly physical, absorb the rays and release the energy as heat. The science of it is pretty cool!

How do I use sunscreen correctly?

You should apply sunscreen every day to any area of the skin that will be exposed to the sun. The standard amount to get sufficient protection (the SPF that is promised on the bottle) is 2 milligrams per square centimeter. To approximate this for my face, I use the three-finger method: using the amount of sunscreen it takes to draw three medium thick lines on my three middle fingers for my face and neck. For my limbs, I use about a teaspoon per limb.

It’s also important to remember that you can’t just apply once a day and be done! The SPF wears off after about 2 hours, so in order to stay protected you must reapply at least every two hours (more if you are getting wet, as the sunscreen will wash off even if it is somewhat water resistant).

My skin is sensitive/oily/dry, etc: How do I find a sunscreen that works for me?

I have heard so many people say they would wear sunscreen, but they haven’t been able to find one that works for their skin. I promise you there is a sunscreen that will work for you, but in order to find one you need to understand both the types of sunscreen available and which will work best for your particular skin type.

Types of sunscreen

There are two types of sunscreen available, and they differ based on the type of technology they use to block or filter the sun’s rays.

Physical, or mineral, sunscreens contain active mineral ingredients, such as titanium dioxide or zinc oxide, which sit on top of the skin to deflect damaging UV rays. These are often thicker and can be less irritating, but have a greater tendency to leave a white cast (especially on darker skin tones).

Chemical sunscreens use organic compounds, such as oxybenzone, octinoxate, octisalate and avobenzone, to absorb the sun’s rays as they enter the skin. They are often thinner and for many more enjoyable to wear due to their lightweight nature, but the chemicals in them can be potentially irritating.

Which type of sunscreen is best for me?

This is totally dependent on your skin type and preferences. I use a mixture of chemical and physical sunscreens depending on my needs for that day. Some general guidelines to get you started are:

  • physical sunscreens may work better for you if you have dry skin
  • but they can rub/sweat off more easily, so beware if you are an athlete or outside a lot
  • chemical sunscreens are lighter and often work better for oily or acne-prone skin types

What about moisturizers or makeup that have skincare built in?

I think these are a dangerous scam, and here’s why: you will never be able to use the appropriate amount of your SPF moisturizer or foundation to get adequate coverage, so it is lulling you into a false sense of security. It is much better to apply a normal amount of moisturizer and then use a sunscreen on top that works well for your skin.

My Sunscreen Recommendations

I’ve been testing out many different sunscreens, with the hope of eventually launching a comprehensive guide to nearly all the sunscreen options available on the market (crazy, I know!) In all my testing, I’ve identified three of my favorites that I think you’ll love as well.

My favorite for my dry, acne-prone skin: EltaMD Clear SPF46

What It Is: A lightweight, oil-free face sunscreen to protect acne-prone and sensitive skin.

What It Does: provides protection to your complexion to shield your skin from harmful UVA and UVB rays. It also contains hyaluronic acid, lactic acid, niacinamide and vitamin E.

Price: $36.00

My Thoughts: This is one of my absolute favorite sunscreens! It’s amazing if you’re outdoors, as it hold sup to sweat and the sun. It feels super gentle and absorbs immediately, with no white cast. It doesn’t feel heavy on my skin, and is actually enjoyable to reapply.

A great reef-safe mineral SPF: Love Kinship Self Reflect

What It Is: A sheer, reef-safe, mineral sunscreen for blemish-prone skin.

What It Does: Protects your skin from the sun without clogging pores or harming the environment.

Price: $25.00

My Thoughts: I’ve talked about this in my Love Kinship review, but this is one of my favorite mineral sunscreens. The scent is lovely, the texture so enjoyable to apply, and the effect so beautiful on the skin. It works as a moisturizer, makeup primer and sunscreen all in one. It’s also pretty affordable!

Great for under make up (or in place of foundation): Colorescience Sunforgettable Total Protection Face Shield SPF 50

What It Is: A hydrating, antioxidant-rich mineral sunscreen.

What It Does: offers complete protection from environmental aggressors in a weightless texture that blends invisibly into all skin tones.

Price: $39.00

My Thoughts: This sunscreen does feel a little thick at first, which surprised me, but it blends in nicely and gives me a no-makeup makeup look. It also works well during exercise and is easy to reapply. I’m impressed with it.

Some other sunscreens I’ve heard amazing things about, but haven’t tested for myself yet, are:

  • Keep Cool Soothe Bamboo Sun Essence
  • Black Girl Sunscreen
  • Krave Beauty Beet Shield
  • Naturopathica UV Defense Cream SPF 50
  • Dermalogica Pure Light SPF 50

Final Thoughts

No matter your skin type, you need to be wearing sunscreen. Not only does it keep your skin looking youthful for longer, it also guards against skin cancer. With the wide variety of options on the market, you can definitely find one that works for you.

Did this post help you learn more about sunscreen? Still have some burning questions? Let me know in the comments!

Leave a Comment