14 Need-to-Know Sun Protection Facts


Dr. Neal Schultz

Dr. Neal Schultz

Dr. Neal Schultz is one of the most highly regarded dermatologists in the country. He has been repeatedly featured within the “Best Doctors” lists in New York Magazine, and he's the founder of, where he has posted over 500 videos covering pretty much every skin-related topic imaginable. Given the much buzzed about findings recently published in the Annals of Internal Medicine, which provides scientific backing for what dermatologists have been saying for years: wear sunscreen year-round to prevent wrinkles, we spoke to the Upper East Side dermatologist to find out more about what to look for when shopping for sun protection and how to apply it.

  1. Choose a sunscreen with an SPF between 15 and 30 to make sure you’re getting effective UVB protection (UVB rays cause burning and skin cancer). Make sure your sunscreen is also labeled with UVA protection, which tells you that your sunscreen also effectively screens against the UVA rays, which are they rays that cause premature aging of your skin. Lastly, make sure it’s appropriate for your oil and water skin type so that it doesn’t break or dry you out.

  2. A very common misconception is that sunscreen (aka chemical sunscreen) and sunblock (aka mineral sunscreen) are the same, but they’re really not. Regardless which you’re using they both have the same ability to protect you from the damaging ultraviolet rays of the sun, but they work differently and are made of different chemicals. Sunblock works by reflecting the light from your skin, almost acting like a mirror so that the ultra-violet rays just bounce off, as opposed to sunscreen which coats your skin and acts like a sponge and absorbs the damaging ultra-violet rays to protect your skin.

  3. Sunscreen needs to be applied 20-30 minutes before you go outdoors, whereas sunblock works immediately.

  4. When it comes to the application process, it varies depending on the type of sunscreen you’re using. For traditional chemical sunscreen, the amount that you need to use for your entire body, assuming you’re at the beach and you’re just wearing a bathing suit, is about an ounce in order to get the actual SPF value. An SPF of 50 becomes an SPF of 7 if you haven’t used the full ounce and an SPF of 15 goes all the way down to 4. For your face and neck, you need an amount of sunscreen that’s about the size of a quarter or a third to a half of a teaspoon. For chemical-free sunscreens, you need about a third to half as much as a traditional sunscreen because they're based on the minerals zinc or titanium. When they're manufactured, those minerals are pulverized into very tiny little particles called micronization and, as a result of micronization, those particles are able to give much larger coverage.

  5. If you put too much on, it’s not going to take away from the sunscreen's effectiveness (unlike treatment products which instead of getting absorbed end up sitting on your skin if you over-apply).

  6. All sunscreens should have an expiration date. That said, you don't need to throw out your sunscreen immediately after the expiration date. An expiration date is just the amount of time, usually a year or two, that the manufacturer demonstrated and tested that the sunscreen still works, but in fact, for weeks, months or maybe even years after the expiration date, you can still use that sunscreen and it will give you the full protection that you expected from it when it was first originally manufactured.

  7. The ingredients and fillers used to make sunscreens dictate whether the sunscreen feels chalky or not, as well as the way it's formulated.

  8. Sunscreen has many determinants in its pricing structure. Certain brands, based on reputation, command higher prices and while in theory all SPF 30s, for example, offer you the same protection, the spreadability, tactile finish and general feeling on your skin is all influenced by how the manufacturer formulates it and the vehicle ingredients used, which can all contribute to a three- to fourfold difference in cost of sunscreen.

  9. Sun protection comes in many forms (foams, lotions, etc.). The only vehicle that is inferior are sprays. While their convenience is alluring, it's very easy to miss areas with sprays and the worst sunburns tend to be on people who use sprays and miss areas, particularly on the back of their body.

  10. For people who are active and sweating, their facial sunscreen should be a very light vehicle and alcohol-based, so it evaporates and can’t sweat into eyes or cause stinging and burning.

  11. Many people forget to apply sunscreen to the tops of ears, feet and lips. 

  12. You need to apply your sunscreen before any other skincare product, including makeup, for optimal protection.

  13. Winter or summer, you need to wear sunscreen daily to protect skin against aging UVA rays.

  14. Sunscreen needs to be reapplied after swimming or sweating or every three to four hours because you’re still experiencing insensible perspiration where the rate of perspiration is equal to the rate of evaporation so you don’t feel the sweat accumulating, but you’re still sweating off your sunscreen.