Sunscreen 101

Posted by Azadeh Shirazi MD on

We all need a little sunshine to brighten our day, give us vitamin D, and help us sleep better at night. The sun can also take a toll on our skin, so using SPF is crucial year-round particularly in the summer where the days are longer and the UV rays are stronger. It’s just as important to pick the best sun-care product for you. As a dermatologist, I am dedicated to educating my patients and my readers on the importance of sun protection and its benefits. Let’s do an SPF deep dive to debunk the myths, highlight the benefits, and share some top-notch sun-care products.

Checkout my newest Youtube video for more information on this topic, below!

What Are The Different Types of Sun Rays?

Not all sun rays are created equal 

  • UVA rays: UVA rays have the longest wavelength among the three types of UV rays. They can penetrate deep into the skin and are the primary cause of skin aging. UVA rays can contribute to the development of wrinkles, fine lines, and age spots.
  • UVB rays: UVB rays have a shorter wavelength and primarily affect the outer layer of the skin. They are responsible for sunburns and can play a key role in the development of skin cancer.
  • HEVL (High Energy Visible Light) is the blue/violet band of visible light with a high level of energy. Studies have shown it contributes to premature skin aging, hyperpigmentation, and discoloration.  
What Does SPF Stand For and What Do The Numbers Mean?

Sun Protection Factor. This number tells you how well the product is going to protect your skin from UVB rays. For example, an SPF30 means it will take 30 times longer to get a sunburn with that product than it will without. 

SPF can be categorized into 3 tiers. 

-Low Protect  <SPF15

-Medium Protection SPF 15 - 29

-High Protection SPF 30 - 50+

Anything above 50 is really going to do the same thing as the high protection spfs. If you apply small amounts of sunscreen, higher SPF numbers like SPF100 is beneficial as you’ll need less product. Nevertheless it doesn’t block 100% of the sun’s rays. It’s important to note that SPF speaks only of UVB protection and not from UVA or HEVL.  

General rule of thumb is to use a broad-spectrum SPF 30 or higher to also protect you against UVA rays. Suncare products with mineral blockers and Iron Oxide also offer protection againse HEVL from the sun that comes through windows and visible light from screens and phones. Hydratint BB SPF44 is my favorite broad spectrum sunscreen moisturizer as it offers broad spectrum protection against all forms of light that have the potential to damage the skin leading to discoloration and photo-aging. Plus it hydrates the skin giving you a filter like appearance.

What Is The Difference Between Chemical and Mineral Sunscreens?

The main difference is mineral sunscreens block UV rays whereas chemical sunscreens absorb them. Mineral SPF creams are physical blockers, they sit on the surface of the skin, forming a barrier to block UV rays from reaching the skin. They use ingredients like Zinc oxide or titanium dioxide that tend to be more dense. Chemical sunscreens are like a sponge, they penetrate the skin, absorb the UV rays and convert them into heat before they can cause sun damage. They use ingredients like oxybenzone, avobenzone, octisalate, octocrylene, homosalate, or octinoxate. They tend to be more lightweight with a clear finish.

Is Sunscreen Toxic?

 Sunscreen is generally considered safe when used as directed. However, some sunscreen products may contain certain ingredients that can potentially cause adverse reactions or have environmental concerns. It's important to be aware of these ingredients and make informed choices when selecting sunscreen. Sunscreen ingredients with potential for concern are:

-Oxybenzone

-Octinoxate

These ingredients are also unsafe for the environment, harmful to the ocean’s reef structures.

Which Type Of Sunscreen Is Best For My Skintype?

I personally prefer mineral based sunscreens over chemical based as they are safer for our skin and the environment. Those with sensitive skin may have reactions to chemical sunscreens as they’re more likely to cause irritation.  If you are prone to hyperpigmentation, the heat generated from chemical sunscreen may potentially worsen your condition. Mineral sunscreens are natural and best for sensitive skin types as they’re less irritating, more inert, since they create a barrier on the surface instead of absorbing into the skin. Mineral sunscreens also contain soothing ingredients like Zinc Oxide that are anti-microbial and anti-inflammatory making them most suitable for acne prone skin.

Oily, combination, or normal skin types can benefit from the lightweight and diverse formulations of chemical sunscreens including oil-free or mattifying options. This can be beneficial for individuals with combination skin who may have oilier areas in their T-zone but drier areas on the rest of their face.

Dr. Azi’s Recommended Products:

Hydratint BB SPF44: protects your skin from harmful UV rays while giving you a filter like appearance. Great for a soft summer coverage.

Supergoop Unseen Sunscreen: Broad spectrum SPF40, an oil free formulation that helps hydrate the skin. Clear application, does not leave a white residue with an elegant texture. 

UV Clear SPF Powder: perfect on the go mineral powder sunscreen brush for easy reapplication. Protects from UVA/UVB rays. Only contains 4-ingredients making it ideal for even the most sensitive skin types.

UV Defense Spray: This broad spectrum SPF50 sunscreen is lightweight, sweat-resistant, reef safe, and highly effective for active lifestyles and prolonged sun exposure.

EltaMD UV Clear SPF 46: broad spectrum oil-free formula is particularly appealing for those with acne-prone skin as it includes lactic acid, an exfoliant that encourages cell turnover and Niacinamide to reduce breakouts. 

← Older Post Newer Post →



Leave a comment

MEET THE DOCTOR BEHIND IT ALL

Dr. Azadeh Shirazi, MD is a Board-Certified Dermatologist.

Specializing in medical, surgical, and cosmetic dermatology, Dr. Shirazi received her undergraduate and medical degrees from the University Of Kentucky College of Medicine. After doing a Research Fellowship at Harvard Medical School at the Wellman Center for Photomedicine, she completed her residency training in Dermatology and Cutaneous Surgery at the prestigious Mayo Clinic in addition to completing her training in dermatology and cosmetic surgery at the University of California San Diego.

She has received multiple research scholarships from iconic institutions including Harvard University and the University Of Texas Southwestern Medical Center and has several peer-reviewed publications to her name.