There is so much confusing information online about sunscreen. As a dermatologist, here are the five of the most common sunscreen myths that I've heard over the last 30 years.
Myth #1: If I just tan, I won't burn, and therefore I won’t get skin cancer or wrinkles
First, there is just no such thing as a “safe” tan when it comes to sun exposure. The skin turns brown as its response to attempting to protect your body from damaging rays. Therefore, any tan you do see is your skin’s way of trying to protect itself. I hear frequently - "I used sunscreen, but I now have a skin cancer spot? How is that possible?" While your skin might not be 'burning' given the sunscreen is blocking UVB rays, there are the UVA ryas that can still be cancer causing. That's why it is essential to use a sunscreen that is broad spectrum, meaning it blocks both UVA and UVB rays, in addition to following other best skin care practices, like reapplying, wearing a hat, and avoiding mid-day sun.
Myth #2: I will not get enough Vitamin D if I wear sunscreen
Truth be told, most people are not as obsessed as dermatologists are about sun protection. So that means, unless you are a dermatologist, most people get enough Vitamin D through their daily routine, even when wearing sunscreen. If you or your doctor are concerned about your Vitamin D levels, the easiest and most assured solution is to take a Vitamin D supplement. This is especially helpful if you don’t drink fortified milk, orange juice, etc, or eat a diet that contains many foods filled with Vitamin D already. These are simple and proven ways to balance your Vitamin D levels without putting yourself at risk for skin cancer.
Myth #3: The higher the SPF, the higher the protection.
Several studies show that most people do not apply nearly as much sunscreen as is used in the testing that determines the SPF level. Why does that matter? Because most people tend to apply less than ½ as much as was used in the lab. When you use a higher SPF, it can actually provide the appropriate amount of UVB/burning rays coverage. However, with chemical sunscreens, the higher concentrations can sometimes be more irritating, so try to seek out sunscreen that uses mineral based active ingredients.
Myth #4: I don't need to wear sunscreen on cloudy days
In the summertime, 80% of burning rays still come through the clouds. That means you can see quite a lot of sun and burn quite badly if you are not protected on those cloudy days. But how about the rest of the year? Yes, there are still UVA rays on cloudy days year round. These rays, like we mentioned, can cause damage to your skin's DNA at the deeper layers of your skin and lead to no one's favorite form of skin damage: wrinkles.
Myth #5: My sunscreen will last forever
Sadly, your sunscreen can and will expire. There is a 'use by' date on all sunscreen bottles. Luckily, if you use the suggested amounts of sunscreen daily, your supply will not last you years on end. Further, it's best practice to get a new supply when you are running low, as the sunscreen loses its effectiveness over time, especially the parts that provide UVA protection. Unlike sunglasses or other UV ray protection items, sunscreen is more like a food item. You wouldn't want to eat yogurt after it had been sitting in the fridge half opened for 6 months. It's the same thing for your SPF.