Its impossible for now to get loan and i think 0.5 is really high amount of bitcoin if you have a good collateral you can borrow but if you are just a newbie its impossible right now to find someone who can give you loan..
The site you mention honestly never heard them and its impossible to get a loan online right now because almost borrowers are scammers..
Like
https://btcjam.com and
http://bitbond.com BTCjam is closing and also isn't open for Americans anymore, I have good collataeral as in physical items just no ALT coins.
Physical collateral might work if you meet directly with the borrower.
But when you want to get a loan online with bitcoin easily then of course you need something concrete such as altcoin.
Goodluck for you , there's no otherway unless you have a valid collateral as i mentioned above.