Hi--First post here, with a question about the effectiveness of different sunscreen ingredients in preventing hyperpigmentation like melasma.

I have severe melasma on my face, plus large, dark blotches on my arms and chest. For outdoor activities like golfing and gardening, should I be using a chemical based sunscreen like avobenzone or mexoryl, or should I choose one that contains physical blocking agents like titanium dioxide and zinc oxide? I can tolerate either kind, and am not too conerned about issues of "cosmetic elegance."  I just want the most protective sunscreen possible for those times when I have to be in the sun for several hours. (And yes, I also wear a wide-brimmed hat!)

So which is better for preventing melasma and other hyperpigmentation--chemical sunscreens, or physical ??

TIA,
Anne (who already owns dozens of high-SPF, UVA-blocking sunscreens!)