How To Reapply Sunscreen, According To Experts

We all know how important daily sunscreen application is, but when it comes to how often we should be slathering up throughout the day, many of us aren't so sure. Below, we spoke with two dermatologists for their expert insight on best practices on how to reapply sunscreen, how much you should be using, how to reapply over makeup, and more.

Best Practices for Applying Sunscreen

When first applying sunscreen for the day, there are multiple factors to consider. "The best practice is to wear sunscreen every day, no matter the season or type of weather," explains Dr. Jaimie DeRosa, a double board-certified plastic surgeon and founder and lead plastic surgeon of DeRosa Center Plastic Surgery. "Yes, even on a dark, cloudy winter day, you need sunscreen—it should be the last product that you apply during your morning skincare routine, and look for a sunscreen with an SPF of at least 30." Whenever possible, also try to have your sunscreen on for at least 15 minutes before going outside into the sun, and make sure to apply product to your décolleté and neck, too.

How Often Should You Be Reapplying Sunscreen?

Sunscreen should be reapplied every two hours when outside or exposed to the sun. " I make it easy on myself and just keep a small bottle or tube of sunscreen in the bag I'm carrying and in my medicine cabinet, just like you do for lip balm," says Dr. DeRosa.

Best Tips for Reapplying Sunscreen to Your Body

Sometimes, it can be hard to remember to apply sunscreen throughout the day, let alone in the morning before starting your day. "Although it can be tough to reapply sunscreen after swimming or sweating, it is essential," explains Dr. Tracy Evans, a board-certified dermatologist, Mohs surgeon, and medical director of Pacific Skin and Cosmetic Dermatology. "When reapplying, make sure to shower or towel off, and then reapply—spray sunscreens can be helpful when you are super active, but make sure to rub them in and make sure you apply enough fluid."

Like the face, you want to reapply sunscreen to your body every two hours when outdoors or exposed to sunlight. "Any part of the body that is open to air can get sun damage, such as sunburns and longer-term issues such as loss of skin elasticity, wrinkles, and hyperpigmentation," explains Dr. DeRosa. "When you're sweating a lot, try to use a product that is more resistant to sweat, so that it's not dripping down into your eyes or flying off your skin with the sweat. There are a lot of high-quality sunscreens out there these days that are specifically formulated for sweating and water-immersion and also have different methods of application, such as a spray or rub-on stick."

Best Tips for Reapplying Sunscreen on Your Face

Dr. Evans recommends using powder sunscreen to touch up skin throughout the day. "Try Colorescience Brush-On Sunscreen Mineral Powder ($69, amazon.com) or Supergoop! Re)setting 100% Mineral Powder Sunscreen SPF 35 PA+++ ($30, sephora.com).

Dr. DeRosa also loves the ZO® Skin Health Sunscreen + Powder Broad-Spectrum SPF ($65, zoskinhealth.com). "It is slightly tinted, has an easy-to-apply brush applicator, and also absorbs the oils on the skin to help decrease shininess—it won't mess up your makeup either," she says.

How Much Sunscreen Should You Use Every Day?

Get a highly rated face sunscreen and apply it as you would your moisturizer—usually a quarter-size amount. "You want to have enough product applied to give proper coverage, so don't skimp on your sunscreen," says Dr. DeRosa. For the body, Dr. Evans advises one ounce (equivalent to one shot glass) of sunscreen.

What to Look for When Shopping for a Sunscreen

According to Dr. DeRosa, there are three things to look for in a sunscreen: UV coverage, ingredients, and "how it wears," so to speak. "Look for those with 'broad spectrum' UV coverage—specifically, you want to be sure that the sunscreen you're using blocks both UVA and UVB rays," says Dr. DeRosa. "An easy way to remember the difference between UVA and UVB is that the UVA sun rays cause the skin to age, and the UVB rays are bad and can cause skin cancer."

Additionally, you want to look out for ideal ingredients when it comes to sun protection. "Well formulated sunscreens will have ingredients that effectively block UVA and UVB rays and also may address skin concerns, such as redness or acne," says Dr. DeRosa. "The two main ways that sunscreens work are with a physical or a chemical barrier—by and large, the physical sunscreens are safer because they don't absorb into the skin, but instead sit on top of the skin to prevent the damaging rays from doing harm."

Titanium dioxide and zinc oxide are "physical" barriers to the sun and now most high-quality sunscreens are micronized, which means they go on smoothly and don't leave a white residue. "Other ingredients that can give additional benefits are niacinamide (Vitamin B3), lactic acid, and Vitamin E," explains Dr. DeRosa. "The niacinamide is an anti-inflammatory and helps to decrease redness, so it's great for those with skin conditions such as rosacea and acne."

Finally, the "wear" or "cosmetic elegance" of the sunscreen is a factor to consider. "I look for those that apply easily and smoothly, don't leave a white residue, and, when desired, also give a healthy tint to my skin," says Dr. DeRosa. "As a facial plastic surgeon, some of my favorites are EltaMD® Skincare's UV Clear Broad-Spectrum SPF 46 (it comes in Tinted and non-tinted) ($37, amazon.com) and ZO® Skin Health's Sunscreen + Powder Broad-Spectrum SPF 45 Medium ($65, zoskinhealth.com)."