Propecia, Rogaine, laser and PRP are the only modalities approved/released by the FDA for retention and enhancement of the native hair.  These work in different ways and are thus, synergistic when used simultaneously.  That being said, there are many practitioners getting involved with PRP with results that are negligible.   Unfortunately, and you would think that everyone would get together to compare notes and see what works and what doesn't, everyone just seems to be doing their own thing.  I would encourage you to do a lot of research and review before and after photos.  Additionally, there are plenty of published studies that can help guide you.

Good luck.