Personal lender, highest interest rate?

[Jessica Dold]

I received a private loan from a family member for a reno as well as some help in labor. Wanting to potentially pay a higher interest rate on this loan instead of paying cash out for the labor that was contributed. Looking online I found a "usery rate" by state for the highest rate that can be charged. Is this what I need to be referencing or is there another set limit for loans? Thank you!