Debunking Common Myths About Sunscreens: A Dermatologist's Perspective

Dr. Marc-André Doré

Monday, July 24, 2023

As a dermatologist, one of my primary goals is to help my patients protect their skin from the sun's harmful ultraviolet (UV) rays. Sunscreens play a crucial role in this process, but there's a lot of misinformation circulating about these products. In this blog post, I'll debunk some of the most common myths about sunscreens and provide you with the facts, backed by scientific research, so you can make informed decisions about your skin's health.

Myth #1: Sunscreens with higher SPF provide significantly better protection

Fact: While sunscreens with a higher sun protection factor (SPF) do offer more protection, the difference between SPF 30 and SPF 50, for example, is minimal. SPF 30 blocks approximately 97% of UVB rays, whereas SPF 50 blocks around 98%. It's essential to apply sunscreen generously and reapply it every two hours or after swimming or sweating, regardless of the SPF.

Myth #2: Wearing sunscreen prevents vitamin D production

Fact: While sunscreens do reduce the skin's production of vitamin D, studies have shown that regular sunscreen use doesn't typically lead to vitamin D deficiency. To maintain healthy vitamin D levels, you can include vitamin D-rich foods in your diet or take supplements as needed. It's essential to consult your healthcare provider for personalized advice.

Myth #3: You don't need sunscreen on cloudy days

Fact: Up to 80% of the sun's harmful UV rays can penetrate clouds, so it's essential to wear sunscreen even on overcast days. Additionally, UVA rays, which contribute to skin aging and the development of skin cancer, are present throughout the day, regardless of the weather. Make sunscreen application a daily habit, regardless of the forecast.

Myth #4: Sunscreen is only necessary for fair-skinned individuals

Fact: People with darker skin tones may have a lower risk of developing skin cancer, but they are not immune to it. Moreover, melanoma tends to be diagnosed at a later stage in people with darker skin, leading to poorer outcomes. Regardless of your skin tone, it's essential to protect your skin from harmful UV radiation using sunscreen and other sun protection measures.

As a dermatologist, I cannot stress enough the importance of using sunscreen and practicing sun safety. By debunking these common sunscreen myths, I hope to encourage you to take better care of your skin and make informed choices when it comes to sun protection. Remember, sunscreen should be used in combination with other sun protection measures, such as wearing wide-brimmed hats, sunglasses, and protective clothing, and seeking shade during peak sun hours (10 a.m. to 4 p.m.).

Here are some additional tips for effective sunscreen use:

  1. Choose a broad-spectrum sunscreen that protects against both UVA and UVB rays, with an SPF of at least 30.

  2. Apply sunscreen generously, using approximately 1 ounce (a shot glass full) to cover your entire body.

  3. Apply sunscreen 15-30 minutes before sun exposure, allowing it to absorb into your skin.

  4. Reapply sunscreen at least every two hours, and more often if you're swimming, sweating, or towelling off.

  5. By incorporating these sun protection practices into your daily routine, you'll be taking crucial steps toward maintaining healthy, youthful-looking skin and reducing your risk of skin cancer.

Stay informed about sun protection and skincare by following our blog, and don't hesitate to reach out to your dermatologist or healthcare provider for personalized advice. Remember, prevention is the best medicine, and taking care of your skin now will benefit you for years to come.


American Academy of Dermatology. (n.d.). Sunscreen FAQs. Retrieved from

Norval, M., & Wulf, H. C. (2009). Does chronic sunscreen use reduce vitamin D production to insufficient levels? British Journal of Dermatology, 161(4), 732-736.

American Cancer Society. (2019, February 20). How Do I Protect Myself from Ultraviolet (UV) Rays? Retrieved from

World Health Organization. (n.d.). Sun Protection. Retrieved from

American Academy of Dermatology. (n.d.). Skin Cancer: People of Color. Retrieved from

American Academy of Dermatology. (n.d.). How to Select a Sunscreen. Retrieved from

U.S. Food and Drug Administration. (2020, July 01). Sunscreen: How to Help Protect Your Skin from the Sun. Retrieved from

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