An essential part of every skincare regimen 365 days a year, rain or shine, sunscreen helps protect your skin from damaging UV rays. Read on to learn about the benefits of sunscreen and find answers to common questions, such as “How does sunscreen work?”, “How long does sunscreen last?” and “Does sunscreen expire?”
The goal of any sunscreen is to help shield your skin from harm caused by exposure to the sun, and a broad-spectrum formula that helps protect against UVA and UVB rays is essential for all skin types and ethnicities, including yours. Sun protection is imperative when spending prolonged periods of time outdoors; however, it should also be applied every morning to help prevent accumulated damage caused by shorter exposure intervals and indirect sunlight (like while driving or walking to and from your car). Available in lotion, cream, stick, and other formulations designed for babies, children, and adults, no matter what your age or lifestyle, there’s an effective, broad-spectrum sun protection product for you. But the key to getting the benefits of sunscreen and maintaining healthy skin is applying it as directed.
The main benefits of sunscreen when using a broad-spectrum sun protection product are helping to protect your skin from UVA and UVB rays and minimizing the damage that can lead to early signs of skin aging and skin cancer (when used as directed with other sun protection measures). In addition, sunscreen products can be specially formulated to provide other benefits for your skin, such as extra moisture, and may contain beneficial ingredients like soothing niacinamide and ceramides to help restore your skin’s natural protective barrier.
However, it’s important to keep in mind that although effective for helping to protect your skin from UV rays, sunscreen alone is not enough, especially when you’re at the beach, by the pool, or spending a significant amount of time outside. For comprehensive sun protection, it’s best to wear protective clothing (including a hat and sunglasses), seek shade when possible, and avoid direct sun exposure during mid-day hours.
How does sunscreen work?
Sunscreen products are designed to help prevent sunburn, and broad-spectrum protection is essential to help shield your skin from UVA and UVB rays. When UV rays enter the skin, they disrupt your cells’ normal growth and function, and they break down your skin’s collagen and elastin (which leads to lines and wrinkles).
Sunscreens work in one of two ways, depending on the UV filter ingredients in your sun protection product. Sunscreens with chemical-based ingredients, such as homosalate, work by sinking into the top layers of your skin and absorbing UV radiation before it can damage your skin cells. Mineral (also called physical) sun filters, like zinc oxide and titanium dioxide, create a barrier on your skin’s surface that reflects UV rays off the skin. Some sun protection products include a mix of both chemical and mineral sun filters.
How long does sunscreen last?
The recommended amount of sunscreen required to protect your entire body is one ounce (or a shot-glass sized amount). Once applied, sunscreen is effective for up to two hours—or less when swimming, sweating or toweling off—which is why it’s important to reapply9 after these activities or at least every two hours. A water-resistant sun protection product will be labeled as effective for up to 40 or 80 minutes before it must be reapplied. You must use any sun protection product as directed.2
This also leads to the question, “Does sunscreen expire?” Yes, it does, which is why there is an expiration date on the packaging. But with this in mind, sunscreens are often left exposed to sunlight and extreme heat for hours at a time, which can reduce their effectiveness well before the expiration date. That’s why it’s important to protect your sunscreen from excessive heat and direct sun.