Dear Dr. Irwin, I’m so grateful for your site—incredibly helpful in navigating the confusing world of skincare. I notice that you recommend a high percentage of zinc oxide or titanium dioxide in sunscreens for the best protection. I try to adhere to that advice and sometimes turn down high SPF rated products because the actual active zinc or titanium dioxide is low. For example, a couple of physical sunscreens say they are SPF 50 but only have around 6-9 percent zinc oxide—too low. I instead opt for sunscreens that have the active physical blockers more in the high teens (18-20% zinc oxide) but at a lower SPF, like SPF 35. Recently I’ve seen some YouTube dermatologists saying that the actual percentage doesn’t matter and to instead go by the actual SPF rating. Dr. Dray is one of them (I’ll paste a link at the bottom). I‘m not requesting you throw shade here but I’m curious which is the best guidance for sunscreen. As always, thank you for your time and effort in educating all of your readers. You’ve made my skin better. Best, EJ Thank you and I’m so glad you wrote this. I’m starting to thinking there’s need to be a new site that just lists and refutes the weird, inaccurate and crazy stuff we all see on the web every day.
Some key facts about sunscreens:
High SPF (over 30-40) is not needed …or even advisable:
Why? Because the SPF ONLY refers to UVB, and does not include UVA. And because an SPF 30-40, properly applied, gets you about a 92-95% block of UVB. The SPF 50, 60, 70 etc. just buys you a lot more chemical exposure for very little extra UVB protection. It’s a marketing trick.
The only sunscreen ingredient that blocks UVA well is zinc oxide.
We all need zinc, ideally 8-20% in our sunscreens. Zinc blocks by far the most UVA. The next best thing, at present, is titanium and it’s not very close. Also, I can’t help but wonder, where does nanoparticle titanium go? Zinc is a natural mineral we can use in our bodies. Stick to lower titanium and higher zinc sunscreens.
Is that web info you are reading correct?
It’s so tough now, with all sorts of people claiming whatever! But I’d say ignore the noise as much as possible and go to reputable sources like your dermatologist, Web MD or here :). Oddly, a number of the “web dermatologists” aren’t actually board-certified dermatologists. It’s a crazy world!
Hope this helps,
Director, Madison Skin & Laser Center
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