Inner root sheath

Although the inner root sheath is not directly responsible for the production of new hair cells, it is closely related to the hair matrix and the dermal papilla. It is therefore closely linked to the structures that control actual hair growth.

In laser hair removal, the inner root sheath is not a primary target structure. The matrix cells and the dermal papilla are crucial, as they regulate hair growth. Nevertheless, the inner root sheath is indirectly affected: the heat generated when the laser energy is absorbed in the melanin of the hair shaft and the hair root destroys the vital structures. As soon as the hair matrix and hair papilla lose their function, the inner root sheath also degenerates, as it is no longer supplied and continuously renewed. In this way, damage to the inner root sheath indirectly contributes to permanent hair loss.