Permanent hair removal with a diode-pumped Nd:YAG laser: a pilot study using the direct insertion method

Area of Science:

• Dermatology
• Laser Medicine
• Aesthetics

Background:

• Permanent hair removal remains a challenge despite extensive research into laser systems.
• Current methods often lead to epidermal damage and complications like pigmentation changes, especially in darker skin tones.
• Indirect laser energy delivery to the hair bulb through the epidermis is a key limitation.

Purpose of the Study:

• To achieve permanent hair removal using a diode-pumped neodymium:yttrium-aluminum-garnet laser system with an insulated optical needle.
• To establish optimal laser parameters for effective, quick, and minimally painful hair removal.
• To ensure no long-term medical complications arise from the treatment.

Main Methods:

• A diode-pumped Nd:YAG laser system (1,064 nm wavelength, 500 mJ/burst) with adjustable pulse width (200-500 µs) and burst frequency (100-200 Hz) was employed.
• An insulated optical needle (130 µm diameter) was used to deliver laser energy directly into individual hair follicles.
• Three bursts of 300 mJ each, with 300 ms intervals, were applied to 200-300 terminal hairs on the shins of 5 volunteers, with follow-up for 18.5-30 months.

Main Results:

• Permanent hair loss of 76%-94.3% was observed in 60% of volunteers after 6-30 months.
• One volunteer experienced significant thinning of regrown hair (34.8% loss), while another had minimal reduction (22.8% loss) with coarse regrowth.
• No adverse effects on skin texture, sensation, or color were noted in any participant.

Conclusions:

• The direct insertion optical method (DIOM) effectively delivers laser energy directly to the hair bulb.
• DIOM achieves permanent hair removal in a majority of subjects (60%) without significant medical complications.
• This technique presents a promising advancement in achieving long-term unwanted hair reduction.