In my experience nobody asks me, their friend, for a (nontrivial) loan unless they've exhausted more conventional lines of credit. Bank loans, credit cards, getting their parents to bail them out.
The friends who I'd rely on to pay their debts don't need $500 from me to help cover their rent this month. And the friends who are already struggling with credit card debt ain't good credit risks, and don't need more debt added to the pile.
I'd sooner just gift them the $500 in the first place.