Platelet-rich plasma is derived from a person's blood (her own blood is the safest and what we use in the clinic) by harvesting it and separating plasma from red blood cells by centrifugation. The result is plasma is enriched with platelet-derived growth factors that promote tissue repair and wound healing.
Probably better known as the "vampire facial", this treatment injects a person's own PRP under the skin on certain areas of the face to stimulate the growth of certain vital tissues. Uneven pigmentations can even out on the skin, not just on the face actually as new healthier cells are encouraged to grow. So, for melasma, this could be one of the treatments to get definitely.
It is the same idea for the hair but it is injected in the scalp. Of course, there are reports of its effectiveness in helping hair grow back.
This is a procedure which aims to improve female sexual function by injecting her own PRP into the vagina.