Laser Hair Removal 101 (Part 1)

Laser Hair Removal 101 (Part 1)

Next to facial, laser hair removal is probably the most commonly performed cosmetic procedure in the Philippines, with underarm hair as the most unwanted. The basic principle behind laser hair removal is selective heating of melanin in the hair follicle, while keeping the rest of the skin unharmed. Dark objects absorb light, so laser energy can be absorbed by melanin in the hair and skin. Light skin and dark hair is an ideal combination, producing the best results, but new lasers are now able to target black hair in darker skin tones.

Many clinics still offer hair removal by intense pulsed light (IPL) and commonly but incorrectly promote this as "laser hair removal.” IPL devices use full light spectrum from xenon lamps, and are therefore technically not lasers.  Lasers use a single wavelength, leading to a more precise and effective targeting of hair follicle.

Laser hair removal has become popular because of its speed, safety, and effectiveness, although results will depend upon the choice of laser technology used. These lasers are characterized by their wavelength, measured in nanometers (nm).

Alexandrite (755 nm) is used only on pale skin and has the highest pain score. Nd:YAG (1064 nm) is the gold standard for olive (type IV) and dark (type V) skin. Diode (810 nm) laser is the gold standard for pale (type I) to medium (type III) skin, and has now been made safer and virtually painless with the new Super Hair Removal (SHR) technology. 

Diode laser is the best option for the typical Filipino skin, which has light brown (type III) to fair (type II) skin tone. Painless diode laser is available at all SkinStation branches.

Spot size, or the width of the laser beam, affects treatment. The width of the beam should be about four times as wide as the depth of the target. Usual spot size used is about the size of a fingertip (8-18 mm). Larger spot sizes help laser light penetrate deeper and make treatments more effective.

Lasers must have a range of pulse width or pulse duration of 5 to 100 milliseconds. Longer pulse widths are safer for darker skin, but shorter pulse widths are more effective. Pulse width must be matched with the right fluence or energy level (measured in Joules/cm2) necessary to disable the follicles. Fluence levels of 10 to 30 J/cm2 are typically used. Although a higher fluence level can be more effective, it can also mean more pain.

Laser energy can have cumulative effect when introduced repetitively in the same target area. Using this principle, it is now possible to avoid painful laser procedure with the use of low fluence (4-8 J/cm2) and high repetition rate (10 pulses per second). This is commonly referred to as Super Hair Removal (SHR). Diode lasers with this new technology are virtually painless and as effective, making SHR a popular alternative to waxing in Brazilian hair removal. (Part 2 will be published on June 19, 2012.)

______________________________________________________________________________________(Updated on February 21, 2013) This was published in the Lifestyle Section of Manila Bulletin on June 12, 2012. The author is the CEO of SkinStation. He received the 2011 Outstanding Chemist Award from Professional Regulations Commission for his achievements in the field of cosmetic chemistry. He can be reached at fred.reyes@skinstation.ph.