Laser hair removal involves the thermal (heat) destruction of hair follicles by targeting the pigment melanin. The treatments vary depending on the patient. The highest tolerable fluence (density of light) and largest spot size are generally recommended for best results. However, excessive fluence may cause adverse effects.

Anesthesia is usually used only when sensitive areas are treated (e.g., upper lip, bikini line), although it may be used for some patients regardless of the treated area. A topical anesthetic cream is applied one to two hours prior to treatment and wiped off just before treatment.

Selective cooling of the top skin layer (epidermis) helps to reduce skin injury, while enabling the laser to penetrate deeper into the skin. Cooling systems that may be used include:

• Refrigerated aqueous gel. A thick layer of cooled gel is applied before the delivery of laser pulses.
  
  
• Conductive cooling. A chilled glass or sapphire window hand piece is placed directly on the skin.
  
  
• Evaporative or dynamic cooling. Short bursts of cryogen (cold liquid) are delivered automatically before the delivery of each laser pulse.
  
  
• Chilled air cooling. Chilled air is circulated over the skin by means of a hand piece.

During the laser treatment, the technician, patient and others within the room must wear eye protection to prevent the laser from penetrating their eyes and causing damage. The treatment itself feels like a rubber band snapping or warm pinpricks against the skin. Mild to moderate pain may be normal in some patients. However, intense pain may signal other problems and must be immediately reported. In these cases, the treatment may be immediately stopped. Pain often signals that the laser’s settings need to be adjusted.

The duration of the treatment depends on the size of the area treated and may last from a few minutes to several hours. With each light pulse, the targeted hair shaft is immediately vaporized. The plume produced by this has a characteristic sulfurous smell. Laser vacuums are typically used to reduce the odor.