Kind of risky deal for you and to anyone who's going to do that. Well, you'll only assure them through words but if you'd going to be providing contracts with attorney sign then maybe there will be many investors that shall invest on your bankroll.
Lending money to a friend is always a problem, because if you do so and they do not pay you back, and you ask them about when you can expect to receive their payment they will get offended by the question, as many of those friends expect that you will simply forget about the debt they have with you and some of them may even have the guts to ask you more money, so unless that money is supposed to be used for an emergency I avoid lending money to a friend.
This is for real. Lending a money to a friend and even to a relative result into having a problem. It's better not to get offended by yourself because they can't pay and you can't collect money on them that they owe you. Because at most times, they'd reason out to you that they can't pay you for so many reasons. So instead of you being disappointed with them not able to pay you, it's better to disappoint them while you and your money won't be disappointed to yourself.