PRP or PRP Prolotherapy  – is a treatment for acute or chronic musculoskeletal injury or pain. The main difference between PRP Prolotherapy and dextrose Prolotherapy is the solution being used.

The use of concentrated growth factors is considered by many to be an exciting and new cutting edge therapy that can stimulate tissue repair, and regenerate weakened torn or damaged ligaments, ligaments and joints.

PRP for cosmetic purposes and pain.
PRP is derived from your own blood. After filtering out the rest of the cells and plasma, a small amount of platelets remain. This highly concentrated amount of platelets — from 3 to 10 times that of normal blood — can be injected into the damaged areas and catalyze the growth of new soft-tissue.
Blood platelets contain potent growth factors necessary to begin tissue repair and regeneration at the injury site. Concentrated platelets contain large reservoirs of growth factors that have the potential to greatly accelerate the normal healing process, naturally.
some info can be taken from here- sports injuries etc.