Next on the hair removal scene, came Thermolysis.  In 1923 Dr. Bordier, of Paris, France wrote an article on the use of high-frequency, alternating current for hair removal.  He named the process “Thermolysis” to reflect its ability to destroy tissue by using heat rather than a chemical reaction.  Thermolysis allowed for much speedier treatments in each follicle and did not seem to be as painful as Galvanic Electrolysis.  It was believed that the high frequency quickly cauterized the nerve endings surrounding the follicle, thereby making it more tolerable than Galvanic Electrolysis. 

In spite of the speed at which clinicians could work using   Thermolysis, electrologists were slow to accept the method in the 1920s and 30s because the machinery for creating high-frequency current was crude and cumbersome for use in hair removal.  It was not until the 1940s that equipment became commercially available and thermolysis became a popular method of hair removal.  It has the advantage of speed over galvanic electrolysis, but requires insertions that place the tip of the needle--where the greatest heat occurs--directly on the germ cells and food source.  Since follicles are not uniform in size or shape, perfect insertions are not always possible, giving rise to a much higher rate of regrowth in the treated follicles and the need for more numerous treatments of the same area.

Dr. Henri St. Pierre of San Francisco, a pioneer in the use of high-frequency, was one of the first practitioners to recognize its shortcomings and began seeking a method of combining the 2 electrical currents simultaneously.  He wanted to combine the efficiency of galvanic current with the speed of high-frequency current. 

Eventually, St Pierre teamed up with an electrical engineer by the name of A.R. Hinkel, to solve the problem and in 1945 the first blended current epilator received a patent.  Hinkel went on to receive certification as an electrologist and after many years of practice and research, Hinkel wrote the definitive textbook on Electrolysis, Thermolysis, and The Blend, in 1968.