DIY galvanic hair electrolysis: a soldering iron, a car battery, and a pop can

A hobbyist documents building a homemade galvanic hair electrolysis machine, the only FDA-recognized permanent hair removal method. Galvanic electrolysis works by inserting a needle probe into a follicle and passing DC current between it and a second electrode on the body, generating sodium hydroxide that destroys the follicle. The dose is measured in lye units (LU), where 1 mA for 1 second equals 10 LU, making the math trivial: integrate current over time until you hit the target.

The initial prototype was deliberately crude — a car battery, potentiometer for current limiting, ammeter for monitoring, and a pop can held in the off-hand as the return electrode. Squeezing the can modulated resistance and current. It worked: a follicle pulled cleanly with no resistance after treatment. Pain was reportedly comparable to laser. The author then upgraded the needle handpiece by exploiting the fact that female DE-9 connector pins grip standard electrolysis needles snugly, and 3D-printed a custom pen housing in FreeCAD. A polarity warning is called out explicitly: reversing leads generates hydrochloric acid in the follicle instead of lye, risking scarring.

The writeup ends mid-build as the author moves toward a full automated unit with regulated current, foot-pedal activation, automatic shutoff at target LU, and ramped current profiles to reduce pain. It’s a clean example of hardware-hacker culture meeting a domain (medical aesthetics) where commercial gear is wildly overpriced — with the usual asterisks about doing electrical procedures on yourself with zero medical training.