Electrology is either of two electrical epilation methods for the permanent removal of human hair. A practitioner of electrolysis as the term is used in epilation is called an electrologist (or sometimes electrolysist in the United Kingdom).
Three methods or “modalities” are used in electrology. One method known to electrologists as galvanic (named after Luigi Galvani) uses a person’s body as an electrolytic cell. Another method is known as thermolysis, RF, shortwave or diathermy. Galvanic and thermolysis are often combined in a method known as blend, developed by Arthur Hinkel in 1948, which uses both RF and direct current, combining many of the advantages of galvanic and thermolysis. All three of these methods use a metal probe 50 to 150 µm (0.002 to 0.006 inches) in diameter which is inserted into the hair follicle to the depth of the dermal papilla or hair matrix, which is the site of formation of hair from highly mitotic and keratinized cells.
Galvanic electrolysis was first reported in the medical literature by ophthalmologist Charles Michel in 1875 to remove ingrown eyelashes in patients with trichiasis. A galvanic epilator is essentially a positive ground power supply that delivers 0-3 milliamperes through the body. The follicular probe is the cathode of an electrolytic cell. Sodium hydroxide formed at the cathode by the process of chemical electrolysis kills the hair matrix cells. Modern galvanic epilators automatically adjust the voltage to maintain constant current.
Thermolysis was developed in the 1920s. A thermolytic epilator is essentially a radio transmitter, usually with an output of about 0-8 watts at a frequency of 10.56 MHz. RF energy emanates from the probe tip to tissue within about a millimeter. Thermolysis works by heating the hair matrix cells to about 48°C, causing electrocoagulation.
Thermolysis allows more depilations in less time, typically 1-4 seconds per insertion, compared to 15 seconds for blend to several minutes for galvanic. On the other hand, the galvanic and blend methods are more forgiving of practitioner insertion and treatment energy setting errors. All three methods, when properly performed, can be thorough at destroying the hair matrix cells, and leaving follicles incapable of regrowing hair.