As a dermatologist, I find myself talking about sunscreen…a LOT. Sunscreen is one of my favorite topics because protection against skin cancer and photoaging is something that everyone should be concerned about, whether you are young or old, male or female, and no matter what ethnicity you are. Since I find a lot of false information floating around out there about sunscreen, I want to take this opportunity to share some of my pearls about UV protection. Why should I use sunscreen? The sun produces ultraviolet (UV) radiation in the form of UVA and UVB. UVA is responsible for photoaging, meaning leathery textured skin, sunspots, and wrinkles with repeated exposure (if you haven’t seen this before, check out this photo of photoaging on just half of this truck driver's exposed face here). UVA is also associated with indoor tanning, and has been linked to the development of melanoma. UVB radiation, the one responsible for sunburns and delayed tans, actually damages your DNA and that can predispose you to developing skin cancers. So sunscreen is your invisible shield that protects your skin from these harmful UV rays. Which sunscreen should I use? I have made a vlog in the past about different sunscreens for different skin types here. Basically, if you have sensitive or allergy prone skin, I would stick to physical blockers, meaning sunscreens that contain zinc oxide or titanium dioxide. Chemical blockers such as avobenzone can be more allergy-inducing. If you’re acne prone, I recommend non-comedogenic sunscreens in a less greasy formulation. Folks with dry skin may benefit from a cream or lotion based sunscreen that also moisturizes. Patients with darker skin may find physical blocker sunscreens difficult to rub in completely since they may leave a white cast on the complexion; for these patients, I recommend certain brands such as CoverFX or MD Solar Sciences or Elta MD which go on clear or lightly tinted and not white. How do I use sunscreen? I tell my patients to use a broad sprectrum (blocks UVA and UVB) sunscreen of SPF30 or higher. The idea is that you should apply about 1 oz of sunscreen (a shot glass worth) to cover all the exposed areas. Apply 15 minutes before going into the sun, and reapply every 2 hours. This is hard to do, especially since I have makeup on, but I’ve found the ColoreScience Sunforgettable loose mineral sunscreen powder to be a lifesaver. This is a sunscreen in powder form so it goes on over your makeup. When I’m going to be in the sun for a long time I also try to wear a broad brimmed hat and large sunglasses. Is sunscreen safe to use? I am very invested in this topic because I’ve seen so many false reports of sunscreen causing hormone problems or cancers. I did a deep dive into the actual science behind these claims and summarized it up in a blogpost here. In a nutshell, I found NO EVIDENCE that sunscreen ingredients cause any of the purported outcomes. In most of the cases, the claims are based off of studies in which animals ingested sunscreen ingredients at astronomically higher doses than we would ever be faced with using sunscreens topically. Source
