Electrolysis is the process of permanently removing unwanted hair. In this process, a metal filament called a probe that is as thin as a hair is slid into each unwanted hair follicle. This is done with the utmost care so the probe does not puncture the skin. Upon insertion, a very low electric current is delivered to the follicle through the probe, which causes localized damage to the cell that produces the hair. Most patrons feel only a slight tingling sensation. Electrolysis has the best results in terms of longevity and is the only method of permanent hair removal recognized by the FDA.