Everyone's heard of electrolysis, the only permanent technique for hair removal available before the advent of laser hair removal in the 1990’s.

Electrolysis makes use of an electric current delivered by a needle directly into individual hair follicles. Each individual hair is grasped and an electric current is sent down the hair to heat and destroy the hair follicle. Because only one follicle is treated at a time, the technique is very tedious and time-consuming. The treatment is painful. Many visits to the electrologist are needed to treat even areas the size of a postage stamp (which may include a few hundred hair follicles). Patients may attend treatments weekly over periods of over a year. And the treatment is about 50% effective, meaning about half of the hairs survive treatment.

There are complications from this technique due to the effects of electrical current. Because some skin cells are burned along with the hair follicle, scarring and ingrown hairs may result. Nodules may form. Infection is possible because of the breakdown of the skin barrier function.

The technique is practical only for small areas such as the upper lip and chin. It is completely out-of-the question for large areas such as the back or legs. Although it was introduced in the mid-20th century, the technology is from the 19th century. It is now an antiquated treatment.