How Often You Really Need to Reapply Sunscreen

Sunscreen is the most powerful anti-aging product in any skincare routine. If youâre wearing a broad spectrum SPF 30 daily, congratulations on taking this crucial step towards preventing skin cancer, visible signs of photoaging, and supporting optimal skin health. Just one question: How often do you reapply your sunscreen?
Applying and reapplying sunscreen throughout the day is essential to getting the best protection possible. Unfortunately, many people donât know how often to reapply sunscreen, how much to apply, or which circumstances warrant a fresh layer of sunblock.
When to Apply Sunscreen
The best time to apply sunscreen is during your morning skincare routine. This ensures that youâre protected the moment you start your day.
Many people make the mistake of thinking that they donât need to wear sunscreen because they spend most of their time indoors. However, damaging UVA rays â which cause skin cancer and loss of elasticity â can penetrate windows and cloud cover. Â In addition, not all damaging rays come from the sun. Electronic devices such as computers and smart phones emit blue light, which research shows can accelerate the aging process by damaging skin. Fortunately, physical sunblock ingredients â such as the natural zinc oxide in our Zinc Sheer Mineral Sunscreen â can protect against the effects of blue light.
We formulated our Zinc Sheer Mineral Sunscreen to visibly boost radiance and hydration in addition to providing powerful broad spectrum SPF 30 protection. Bio fermented ectoin supports the skinâs barrier by replenishing moisture while butterfly ginger extract visibly improves radiance by blocking daytime aggressors. Our makeup-friendly formula melts seamlessly into the skin, leaving a dewy finish and providing a smooth, grippy canvas to extend makeup wear.
Itâs also important to make sure youâre applying enough sunscreen to provide the expected amount of protection. Dermatologists recommend applying two finger lengths of sunscreen to your face and neck and about a shot glass full to the rest of your body.
How Often to Reapply Sunscreen
The American Academy of Dermatology recommends reapplying sunscreen every two hours to stay protected while youâre outdoors. You should also reapply immediately after swimming or sweating. That said, many of us spend our days working inside, not outdoors swimming or sweating. So how often should we apply sunscreen indoors?
According to the Skin Cancer Foundation, people who spend most of the day indoors away from windows only need to apply every four to six hours. That said, itâs important to remember that sun damage is cumulative. Itâs therefore best to reapply if youâre heading out to grab lunch, go for a walk, or otherwise expose yourself to the sun â even for just a short time.

As a lifestyle writer and journalist, I love sharing my passion for ocean conservation and obsession with clean beauty. Iâve tried almost every trend and ingredient, and Biossanceâs science-backed formulas are the only ones that consistently calm my reactive skin and make it smoother, clearer, and healthier. Iâm so excited to be on this journey of skincare innovation with Biossance, and to share it with you!