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How to choose which sunscreen to use

Updated: May 19, 2023


Disclaimer: The information in this article is not meant as specific individual medical advice. Please consult your dermatologist or other medical professional about your skin or medical condition.


It is estimated that about 1 in 5 Americans will develop skin cancer in their life time.

Using sunscreen is an important part of a skin care routine. Sunscreen use reduces the risk of sunburn and skin cancers. It also reduces skin aging caused by sun exposure. There are many sunscreens available. I hope this guide will help you choose and use a sunscreen that will protect you from unnecessary skin damage.

Why use sun screen?

Ultraviolet (UV) radiation from the sun causes sunburn, skin aging and skin cancers. UV radiation is generally subcategorized as UVA and UVB.

UVB is the main cause of sunburn and skin cancers. UVA also contributes to causing skin cancers, and is responsible for premature skin aging, wrinkles and age spots.

The main reason for using sunscreen is to reduce the risk of getting sunburns and developing skin cancer, and to reduce premature skin aging from sun exposure.

Which sunscreen should I use?

Broad spectrum

Firstly, look for a sunscreen that is labelled ‘broad spectrum’. This means it protects against both UVA and UVB radiation. As I mentioned above, both UVA and UVB exposure increases the risk of skin cancer. In addition, UVB is the main cause of sunburn, and UVA contributes to premature skin aging. Choosing a ‘broad spectrum’ sunscreen will provide the broadest UV protection

Sun Protection Factor (SPF)

SPF is a measure of how much UVB radiation a sunscreen can filter out. A sunscreen that has a SPF 30 or higher is generally recommended. While higher SPF means higher protection, the increase in protection is not linear. SPF 30 sunscreen blocks about 97 percent of UVB rays.

Water Resistant

Sunscreens are not waterproof or sweatproof. Water resistant sunscreens may last up to 40 to 80 minutes after water exposure or sweating. Hence, it is important to reapply sunscreen after swimming or sweating even if it is water resistant.

Should I use a Mineral Sunscreen or Chemical Sunscreen?

Physical, or mineral, sunscreen contains zinc oxide and titanium dioxide as its main ingredient. These mineral sunscreens sit on the surface of the skin and forms a barrier to block, scatter and reflect harmful UV radiation before they penetrate the skin. As such, they are more likely to leave a white residue on the skin after applying

Zinc oxide and titanium dioxide are inorganic minerals and are less likely to irritate the skin. Hence, mineral sunscreens are recommended for those with sensitive skin.

Chemical sunscreens on the other hand contain carbon based (organic) compounds that transform UV radiation into heat, which is then released from the skin. Common active ingredients fused in chemical sunscreen include avobenzone, octinoxate, oxybenzone and octocrylene.

Chemical sunscreens generally rub easily into the skin without leaving a residue. However, there is a higher chance for the chemical ingredients to cause skin irritation or redness, compared to mineral sunscreens.

How to Apply Sunscreen

It is important to apply enough sunscreen to any exposed areas of skin every day. Typically, an ounce of sunscreen (golf ball size) should be applied to all exposed skin.

It is best to apply a coat of SPF 30 broad spectrum sunscreen about half hour before leaving the house. Then, re-apply sun screen at least every two hours.

When using a spray sunscreen, it is best to spray the sunscreen on the hands, and apply it to the face for more even application.

When you are applying sunscreen to the face in the morning as part of a morning skin care routine, the sequence of use is usually:

  1. Cleanser

  2. Toner or Prescription treatment (if used)

  3. Moisturizer

  4. Sunscreen

Other Sun Protection Measures

Sunscreen use does not completely protect your from harmful damage from UV radiation. Seeking shade during hours of bright sunlight, and wearing wide brimmed hats, sunglasses and protective clothing are equally important.

I hope the information here has been helpful in helping you choose and use a sunscreen.


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