What method of hair removal uses small needles inserted into hair follicles for a permanent effect?

Electrolysis is recognized as the method of hair removal that employs small needles directly inserted into hair follicles. This technique uses an electric current to destroy the hair follicle, resulting in permanent hair removal. The process targets individual hair strands, making it effective for all hair colors and types, thereby providing a permanent solution to unwanted hair.

In contrast, the other methods listed operate differently. Photo-epilation utilizes light-based technology, such as intense pulsed light, to target and reduce hair through the pigmentation in hair follicles but does not guarantee permanent results for all individuals. Laser hair removal is similar; it uses concentrated light to penetrate hair follicles, but results can vary depending on hair color, skin type, and treatments needed for complete removal. Waxing, on the other hand, is a temporary hair removal method that removes hair from the root but does not provide any long-lasting effects as the hair will eventually grow back.

Thus, electrolysis stands out as the only method among these options that achieves permanent hair removal through the effective application of electrical currents in hair follicles.