How does the needle work in electrolysis?

In electrolysis, the needle is a critical component that delivers an electrical current directly into the hair follicle. This current passes through a conductive solution (often saline or the body's own moisture) and causes a chemical reaction or thermal damage to the follicle. The process is designed to destroy the hair follicle's ability to grow hair permanently.

When the electrical current is applied, it generates a heat effect or creates a chemical reaction that effectively weakens or destroys the follicle. This localized action ensures that future hair growth is inhibited, making electrolysis a permanent hair removal method.

The other options do not accurately describe the functioning of the needle in electrolysis. For instance, while heat is generated as a result of the electrical current, the primary mechanism of action is the delivery of that current to the follicle, not heat application itself. Injecting a solution would not be appropriate in the context of typical electrolysis, as the process relies on the current rather than introducing substances into the follicle. Removing the hair follicle is an outcome of the treatment but is not a function of the needle; instead, it is the result of the successful application of the electrical current that destroys the follicle's ability to regenerate hair.