This is a very interesting and unique question! How does donor-ship work for a hair transplant? In a typical hair transplant, the patient remains both the donor and the recipient of the procedure. This is because, the body does not reject it's own cells. Therefore, when the patient becomes the donor, the transplant rates become highly successful. Why can't you use other donors? Though this is theoretically possible, when the graft follicle is taken from another donor, the body tends to view the graft as a foreign body and there are higher risks of rejection unless an immunosuppressant is introduced into the mix, which is deemed medically unnecessary for aesthetic surgery. This is very similar to the concept of organ transplants and the donor (if it's not the patient) would have to undergo the same amount of testing. Nevertheless, this phenomenon is possible if the patient has an identical twin or is already taking an immunosuppressant for other reasons. What is the future of hair transplant donation? Currently, donor grafts are of a limited resource, be it the patient's own scalp or someone else's scalp. The amount of hair follicles present on their scalp is set in stone from the beginning. This is an additional reason why it may make it harder to find someone to donate hair follicles to someone in need. However, recently research and experiments are being conducted revolving around the concept of "hair farms". These farms introduce 3D printed hair follicle grafts which can replace donor grafts and become an endless supply for patients in need. However, by the time this concept comes to reality with good safety standards, there is a long way to go.