Any idea what your friend's body fat percentage is? If it's above 15%, he should stay away from winny for the time being. I also don't really recommend clen for somebody who's too out of shape because side effects include high blood pressure, faster heart rate and overheating.
HGH is milder than the other two and is definitely a good fat loss aid. However, it's usually pretty expensive so he'd better be prepared to shell out some money.
To be honest, it sounds like your friend needs to do a little research on dieting (based on his goals) and hit the gym before considering anything else.