The alexandrite laser is a shorter wavelength system with a specific light energy of 755nm. The long-pulse alexandrite laser achieves deep penetration into the dermis where the hair follicles are located. The heat build-up in the hair shafts disables those follicles in the active growth phase. However, it frequently produces side effects such as pigmentary changes (lightening or darkening of the skin), or worse, for patients of all but quite light skin.

The alexandrite laser produces reddish light just at the limit of visibility at 755nm. Alexandrite lasers have a large spot size (up to 18mm) over which the laser light spreads. It also has a high repetition rate. These properties mean the alexandrite laser is the fastest hair removal laser, and is suitable for rapid treatment of large body areas in patients with complexions that are light to olive in color. The entire back of a person can be treated in less than 30 minutes with an alexandrite laser. Along with the diode laser, the alexandrite is the most widely used laser for hair removal and can be found in many laser hair removal clinics.