A Top NYC Dermatologist Answers Your Burning Sunscreen Questions

In a recent article published by Town & Country, New York dermatologist Dr. Marnie Nussbaum sheds some light on the most common questions surrounding sunscreen. Here are some of the highlights:

Reapplication

"Sunscreen is only effective for a finite amount of time. The UV filters (whether physical or chemical) start breaking down when exposed to light, air, and other environmental factors, particularly if you sweat or get wet. Therefore, we recommend always applying it 15 minutes prior to going out and reapplying every two hours or sooner if you get wet or sweat."

Ingredients

"Always look for a product that says 'broad spectrum,' which means that it protects against both UVA and UVB rays. Overexposure to either can lead to skin cancer. UVA rays can pass through glass, and both can pass through clouds and reflect back from water, sand, and snow. I always recommend mineral-based sunscreens which are physical blockers and more photo-stable. Key ingredients to look for are zinc and/or titanium dioxide. These mineral sunscreens protect the skin like a shield and block the UV rays by deflecting them, and the newer generation does not leave a thick, white cast. Other labels to look for are 'water resistant.' No sunscreen is waterproof or sweatproof. They are tested for water resistance and usually protect for either 40 or 80 minutes. Therefore, be cognizant [of] how long you are in the water. If a product does not have this label, assume there is no protection from water or sweat. And lastly, always look for sunscreen that is SPF 30 or higher. The higher the number, the more protection."

Recommendations

"I love EltaMD UV Clear Broad Spectrum SPF 46 for the face because it contains transparent zinc as well as niacinamide and sodium hyaluronate to moisturize and protect the skin. My top body sunscreens include Supergoop! PLAY 100 Percent Mineral Body Mist SPF 30 with Marigold Extract, which is 80-minute water resistant and reef-friendly. It's a lightweight zinc, which sprays on white, however blends to sheer on all skin tones. It also is super nourishing with marigold, sunflower seed, and chamomile. I also love La Roche Posay Anthelios Sunscreen SPF 50 as it is a mineral-based, lightweight lotion that contains vitamin E, herbal extracts, and antioxidants for anti-inflammatory benefits."