What makes a good sunscreen? Zinc, titanium, other ingredients?

Dear Dr Irwin, do you agree that sunscreen products may use different ingredients / agents to achieve the photoprotection level desired? Are Titanium Dioxide and Zinc Oxide the best agents? Thank you. What makes a good sunscreen? Thank you.

I’m worried I’m going to totally nerd out on you here, but if you look at these ingredients, they all have a UVB job and a UVA job and they all are different in exactly which portion of that harmful light they block.  To make it even  more confusing, they may block totally or only partially (called attenuation).

Bottom Line:   Zinc is the ONLY sunscreen ingredient that totally blocks through entire UVB (290-about 320 nm) and UVA (about 320-400 nm) spectrum.   Titanium does a good job through UVB but only partially blocks UVA and stops short of the full spectrum at about 380 nm.      You need from 5-20% depending on where you live, when you’re out, driving in a car, sports etc.

All other sunscreen ingredients are worse than these two at blocking harmful light rays to skin.   You can see why I nag about protective clothing a lot.   It’s because the sunscreen industry has done a good job of convincing consumers that  sunscreens are doing a better job than they are.

Still…..some sunscreen is almost always better than none at all!!!  🙂

Hope this helps,  Dr. I

Dr. Brandith Irwin, MD

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