The Dos and Don’ts of Sunscreen Safety

Published: August 12, 2021
Gabrielle Pierce
By Gabrielle Pierce, PharmD, MBA
Marissa Brooks
By Marissa Brooks, PharmD, MBA
Hannah Post
By Hannah Post, PharmD

Sunscreen is a product that you apply to your skin to protect it from sunburn and other damage that can lead to certain types of skin cancer. With so many options available, choosing the right sunscreen can be challenging.

What do you need to know about sunscreen?
Every sunscreen has an SPF (Sun Protection Factor) number. The SPF number tells you how long the sun’s rays would take to begin to redden your skin when using that product compared to the time without sunscreen.

There are two types of sun rays—UVA and UVB. UVA reaches the deeper layers of your skin and causes tanning and aging. UVA rays can go through windows and clouds, even when it is overcast. UVB rays can tan and burn the outermost layers of the skin. The intensity of UVB rays changes throughout the day and is strongest between 10am and 2pm. Products labeled as broad-spectrum sunscreens protect against both UVA and UVB rays.

What ingredients should you look for in a sunscreen?
Active ingredients are the components of sunscreen that work together to protect your skin from burning. There are two categories of active ingredients:

    • Mineral sunscreen is also known as “physical sunscreen.” Mineral sunscreen works when minerals, such as zinc oxide and titanium dioxide, sit on the surface of your skin and block UV rays. Since it sits on the surface of the skin, mineral sunscreen does not enter the bloodstream and may be safer for young children and pregnant women.  Mineral sunscreen begins working right away after application.
    • Chemical sunscreen works by using chemicals, such as oxybenzone, avobenzone, octisalate, octocrylene, homosalate, and octinoxate, that soak into the deeper layers of the skin to provide protection from the sun. Chemical sunscreen may take about 20 to 30 minutes to begin fully working.

Experts suggest using products that contain both mineral and chemical sunscreens for full protection.

Inactive ingredients are the components of sunscreen that keep the mixture together so that it can be spread evenly on the skin and stays stable in the bottle through the period of time until the expiration date.

FDA regulation of sunscreen
In the United States, sunscreen is considered an over-the-counter (OTC) medication, which means you do not need a prescription to buy it. The Food and Drug Administration (FDA) regulates the testing and labeling of sunscreen products so that they can ensure that the active ingredients used in sunscreens available for purchase are safe and effective. Ingredients must protect against and remain active against UV rays and be water-resistant. The FDA reviews how much each product protects against both UVA and UVB rays.

The FDA is currently working on an update to the requirements for sunscreen to be sure that all products available for purchase are safe and effective. They are currently reviewing several active ingredients in sunscreens, like the chemicals mentioned above. Until the FDA issues a final decision about their safety, the FDA recommends that you should continue to use sunscreen because it protects you from the sun's harmful rays.

Can medications increase the risk of sunburn?
Yes! Medications that can increase your risk of burning include, but are not limited to:

    • Antibiotics and antifungals such as doxycycline, ciprofloxacin, levofloxacin, ofloxacin, and sulfamethoxazole/trimethoprim (Bactrim)
    • Heart medications such as hydrochlorothiazide, bumetanide, furosemide, diltiazem, and amiodarone
    • Cholesterol medications called statins (atorvastatin, rosuvastatin, simvastatin, pravastatin, lovastatin, fluvastatin, and pitavastatin)
    • Diabetes medications such as glipizide and glyburide
    • Topical medications such as benzocaine, benzoyl peroxide, dapsone, Para-aminobenzoic acid (PABA), acitretin, and isotretinoin
    • Antidepressants such as doxepin, amitriptyline, nortriptyline, imipramine, and desipramine
    • Sulfa-based medications such as sulfadiazine and sulfasalazine
    • OTC medications such as Benadryl (diphenhydramine) and NSAIDs (ibuprofen, naproxen)

Be sure to discuss all OTC medications, prescription medications, and herbal supplements with your doctor or pharmacist, and ask whether they cause sun sensitivity.

DO remember these sun safety and sunscreen tips:

  • DO use a broad-spectrum sunscreen, ideally with 30 SPF or higher.
  • DO apply a generous amount (about 1 oz for each application) to the entire surface of your skin.
  • DO apply sunscreen between 15 and 20 minutes before going outside.
  • DO reapply sunscreen every 2 hours while outdoors. If you are sweating or going swimming, reapply more often.
  • DO use creams for dry skin. Gels are best for hairy skin surfaces. Rub-on sticks may be easier to apply to the face. To apply spray products to your face, first spray onto your palms and then apply to your face.
  • DO limit your sun exposure, especially from 10am to 2pm, and wear clothing that covers your skin to reduce sun exposure (long sleeve shirts, hats, sunglasses, or pants).

DON’T make these sun safety mistakes:

  • DON’T get sunscreen in sensitive areas such as your eyes.  
  • DON’T use expired sunscreen. It does not work as well and may not provide enough protection against sunburn. Throw away any sunscreen that is past its expiration date.
  • DON’T inhale a spray-on sunscreen. Use in a well-ventilated area.

For more information about sunscreen, visit:

By Gabrielle Pierce, Pharm.D., M.B.A.; Marissa Brooks, Pharm.D., M.B.A.; Hannah Post, Pharm.D.

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