If a friend or family members ask for a small loan, of course you should help if you can, but make sure you can afford to lose it.
When large sums are in question however, it’s a different story. It may be hard to say no but if these funds could jeopardize your future, you have to avoid lending large sums of money and offer to help in an other way. Here is a great article you should read before lending money to a friend. At the end of the day, lending money is a business transaction and should be handled in a business-like way.