Trusted site like poloniex will be better than what others are recommended here. To me it better to save and lending your bitcoin were you know your investment is safe. The red sign of losing trust on some members of this forum is a sign of many defaulting and scam there lender. In investment trust is very important and no matter the rate I will advise you to use site like poloniex.
My friend is always telling me this to have my btc loaned in Polo if I am not trading. So that, while it is on standby there in exchanges, it is earning interest. It is also a good and honest way to earn. I am planning to do lend too there in margin trading, if I accumulate more btc