Hair transplantation is a type of autogenous transplant in which the patient’s own tissue is transplanted, therefore there is no risk of a typical rejection reaction. However, there are several “external” reasons why transplanted hair may “not take hold”.
These reasons include the following:
Hair follicles collected from the donor area are stored incorrectly before being placed back into the scalp
Hair follicles are damaged during collecting, dissecting or implanting
Previously undiagnosed / unrevealed inflammation or skin diseases
The procedure takes too long and the collected hair follicles die
Patient mishandling of donor areas following a transplant procedure, including, for example, mechanical damage, sun exposure, sauna visits.
After the hair transplant surgery, there is a waiting period of several months for the results. In the first step, most of the hair will die and fall out, however the transplanted hair follicles implanted in the scalp will remain alive and begin to function in the natural hair growth cycle.
The transplanted hair is collected from the donor area (back and sides of the head, sometimes other parts of the body) where the hair follicles do not have dihydrotestosterone (DHT) receptors, i.e. the hormone responsible for androgenetic alopecia. This means that the follicles transplanted into the recipient area will, in a sense, “desensitize” this zone to the action of DHT. This is because they are genetically indifferent to the effects of dihydrotestosterone. Thus, after a properly performed procedure and with appropriate precautions by the patient , satisfactory results can be expected.