hey doc, i want to physically block all sunrays, my skin is sun sensitive (which means it tans very easily). so, in my case i want sunblocks which protects me from burning and tanning (both). which ingredient is more powerful in my case.... 1. Zinc Oxide 2. Mexoyl 3. Titanium Oxide.... etc and how much %age also is it okay to use Vit C cream before sunblocks? thanks
Which Sunblock? Which Sunscreen?
Doctor Answers 2
Sunblock versus sunscreen
Terchnically speaking a sunblock will physcially block the sun's rays and conceptually the denser the block, the more effective the protective effect. Desitin is almost pure zinc oxide but practically speaking it is not a convenient sunblock. Therefore micronized versions are available. As more concerns are raised with the safety of different wavelengths, sunblocks may make more sense then sunscreens which selectively filter out specified wavelengths and not necessarily provide the broad spectrum protectio of a physical sunblock.
Sunblock and Sunscreen
Practically speaking these terms are used interchangeably. In theory a sunblock is a "physical" ingredient that actually blocks the rays, zinc oxide and titanium dioxide are good examples of this. "Chemical" sunscreens are exemplified by mexoryl and this particular sunscreen blocks both UVA and UVB the broadest.
They are not really "ranked" according to power although true physical blocks may be slightly more effective than chemical blocks at complete blocking of the suns uv rays.