Skincare standards, part 3: Do you REALLY need to reapply sunscreen?

May 11, 2023

If you’re applying sunscreen to your face every morning, you might think you’ve set yourself up for all-day protection. And compared to non-sunscreen wearers, you’re headed in the right direction. But the real question is: Are you reapplying throughout the day? 

That’s right—applying sunscreen during your morning skincare routine might not always be enough to protect your delicate skin from the potential damage of the sun’s UV rays all day long. This begs the question, how often should you reapply sunscreen? Get the answer to that question, plus everything you need to know about reapplying sunscreen so you’re prepared and protected no matter what the day throws your way. 

The skinny on sunscreen: Why is it important? 

One in five people will develop skin cancer in their lifetime. And some of those cases occur because individuals lacked proper sun protection (they skimped on sunscreen usage). In addition to significantly decreasing your chances of developing skin cancer, wearing sunscreen is also important for a few other reasons, including: 

Physical vs chemical sunscreen: What’s the difference? 

The sun emits two types of UV rays. UVA rays penetrate deeper into your skin and can cause premature aging, while UVB rays penetrate only the top layer of your skin. These are the rays that can cause sunburn and increase your risk of skin cancer. 

Physical sunscreen and chemical sunscreen are two types of SPF you can use to protect yourself from UVA and UVB rays. The main difference between the two is how they protect your skin from the sun: 

  • A physical sunscreen, also known as mineral sunscreen, uses mineral ingredients that sit on top of your skin and reflect the sun’s rays away from your skin 
  • A chemical sunscreen uses ingredients that absorb the sun’s rays into your skin. Then, they’re turned into heat and released from your body 

When deciding on mineral vs chemical sunscreen, just know that both types provide much-needed protection against the sun.  

Contributing factors of your SPF’s effectiveness 

There are several factors that contribute to how effective sun protection factor (SPF) is and how long it will last, including the SPF level, how much sunscreen you’re applying and how often you’re reapplying. 

How much SPF are you applying? 

Another factor that contributes to your SPF’s effectiveness revolves around how much sunscreen you’re using when you apply and reapply. 

  • For your face, you’ll want to use about a teaspoon 
  • For your neck, arms and legs, you’ll want to use approximately an ounce of sunscreen (about a shot-glass full) 

How often are you reapplying? 

If you have an action-packed day of outdoor activities, it’s important to reapply your sunscreen at least every two hours. That’s because the longer you’re in the sun, the less effective your sunscreen becomes at protecting against harmful UV rays and sun damage. Once your sunscreen loses its effectiveness, you’re at the mercy of the sun’s damaging rays. 

If you’re spending time in the water, your sunscreen will wash off quickly and you’ll need to reapply more often. Most waterproof sunscreens will tell you how long they’re effective before it’s time to reapply another layer, typically 40 or 80 minutes. 

Tips for daily sunscreen application and reapplication 

Here are a few tips to ensure you’re applying and reapplying your sunscreen properly: 

  • Choose an appropriate SPF level: Aim for a minimum of 30 SPF. If you have fair skin, an SPF of 50 or higher will offer you slightly greater protection 
  • Apply it before going outside: Apply your sunscreen at least 15 minutes before you go outside so that your skin has time to properly absorb the ingredients. This will ensure the sunscreen is most effective 
  • Apply it to bare skin: Leave no patch of bare skin sans sunscreen. Anywhere that isn’t covered by clothes should have a layer of SPF 
  • Be generous with your application: Use as much sunscreen as you need to cover your body adequately 

Find a sunscreen with benefits that make you want to reapply 

So you’ve nailed down the right order to apply skincare products and you finish off with sunscreen, but it’s important to reapply throughout the day. With the right product and a little persistence, reapplying your sunscreen can become second nature. The first step is finding a sunscreen that’s right for your skin. If you have acne-prone skin, a lightweight non-clogging formula is an excellent choice. For individuals who plan on wearing makeup on top of their sunscreen, there are effective sunscreens that also double as makeup primers

References for this information: 
American Academy of Dermatology Website, How to Select a Sunscreen  
Skin Cancer Foundation Website, UV Radiation 
American Society for MOHS Surgery Website, Physical vs Chemical Sunscreens  
Johns Hopkins Medicine Website, Wellness and Prevention 

About the Author

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Jacki Marzano is SoCal-based storyteller and head copywriter at Murad Skincare. She's shaped the voice of some of the most recognized beauty brands in the business, has a penchant for sharing homemade cookies, and believes SPF is the secret to getting carded well into your 40s.