I take the Dupixent pen myself. I usually do it on the top of my thigh or my stomach. It doesn't hurt at all

The stomach hurts less than the thigh.

Hell I never know where to inject! lol

I read 45 minutes also,plus it was suggested by my daughter in law.

The whole point of refrigeration is to preserve what's in it. If left out too long it could jeopardize it's contents. I was told 20-30 minutes and I have reminders go off on my phone as an aid and not forget what day to take it.