Legal Question in Civil Litigation in Pennsylvania

Re: handshake loan contract

Sure. There's only a few types of contracts which need to be in writing (example: a sale of real estate).

An oral contract is perfectly valid and enforceable. It's a little harder to prove, which is why you see those kind of cases on Judge Judy all the time: was it a loan or a gift? So the courts will look at circumstantial evidence and use common sense.