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  • Rajani Katta MD

Choosing the Right Sunblock Means More Than Just Looking At The SPF Factor

Updated: Aug 16, 2020


"What kind of sunblock should I use?"

This is a question that I'm often asked. To start with, choosing the right sunblock means more than just looking at the SPF factor.

1. What do I mean when I say the SPF factor isn't enough? The SPF factor refers only to protection against UVB radiation, the type of ultraviolet (UV) radiation that causes sunburns. You also need protection against UVA radiation, which is the kind that causes aging of the skin. (UVB for burns, UVA for aging) 2. Check the label, and make sure your sunblock provides "broad-spectrum" protection. While national organizations have been advocating for labeling that would indicate the degree of UVA protection provided, that hasn't been approved yet. For now, "broad-spectrum" is the best term to look for. 3. My personal favorite broad spectrum sunblock ingredients are zinc oxide and titanium dioxide. These are ingredients that physically block the sun's rays, and they're the ideal choice for persons with sensitive skin like myself.

4. Most people don't use enough sunblock to actually get the sun protection listed on the label. You need to use a thick layer. How much? One ounce of sunblock is enough to cover the entire body one time. Think about the amount in a 1 ounce shot glass to help you remember this rule.

5. If you're sweating, reapply every two hours. And if you're in water, remember that even waterproof sunscreen needs to be reapplied. 6. If you're relying on your makeup or moisturizer with SPF, remember that that only works if you use enough, meaning a thick layer of makeup. And while a thick layer of moisturizer might be enough for a day spent mostly indoors in your office, if you're going to be outdoors, you're going to need a real sunblock.

The most important rule of all is this one:

The right kind of sunblock is the kind that you're actually going to use. Are you a runner and you can't stand sunblock dripping into your eyes? Then you're probably better off with a sports gel or a sunblock stick. There are lots of different formulations now, so choose the one that feels best for you.

Actually, I take that back. The most important rule is that sun protection means more than just sunscreen. Read this post for the other important steps that you need to take to protect your skin from the damaging effects of UV radiation: Sun Protection Is About More Than Just Using Sunblock

Dr. Rajani Katta is the author of Glow: The Dermatologist's Guide to a Whole Foods Younger Skin Diet. To receive future updates on preventive dermatology and the role of diet, sign up here.

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