I hold on to my boxes for a couple of days out of habit. It used to be to make sure I was happy with a product. It's getting tossed tomorrow.
Interestingly enough, this lipstick has bismuth oxychloride which, in face and eye products, irritates the crap out of me. I just can't use it b/c within 5 minutes I'm itching and breaking out. However, having two of these lipsticks and wearing them for hours, there's nothing weird at all. Go figure. I hope it stays that way.