I am on team Dr Erin regarding sunscreen. I apply once and only reapply if I got really sweaty or I am wiping my face off.
I go to work before the sun rises and return after the sun sets. No sunscreen for me
UVA scatters so much indoors that I donโt worry about it. I also need just a little bit because it reduces blood pressure.
But then I have a wonderful sunscreen that I would wear without any hesitation. So I apply some even though I wonโt get the max SPF 50, I am still happy with the Spf 25 amount that I have on.
This is because sunscreen is quantitative, you need enough to reach the SPF value.