Hair Reduction Laser

Hair Reduction Laser Treatment

Laser hair removal is rewarding to the patient

  • If the indication is correct
  • With proper laser machine
  • With right fluence and pulse width

Basic principles of hair reduction

  1. Selective photothermolysis
  2. Ideal wave length
  3. Selecting important parameters like
    Spot size
    Pulse duration
    Fluence Skin
    cooling [ cryogen sprays/ chill tip cooling/ ice packs/ Zimmer.

What is selective photothermolysis?

  • Laser targets the stem cells in the bulb area of the unwanted hair.
  • The laser light damages the target melanin in the hair follicle without affecting the melanin in the adjoining skin.
  • To achieve the above, duration of the light delivered has to be equal or less than the thermal relaxation time of the hair follicle.

Why wave length is important in hair reduction lasers?

  • Melanin pigment absorbs light across 250-1200nm
  • If wavelength <690nm, oxyhemoglobin is a strong competing chromophore.
  • If wavelength >1000nm, affinity of light for water increases.
  • The optimal wavelength for lasers targeting melanin in hair follicles 690 – 1000nm.

About hair growth cycle

Hair contains melanin only in anagen phase and thus susceptible to injury.  Laser works on the hair in the anagen phase. Hence multiple treatments are required. The spacing between sessions is based on the hair growth cycle.

Adult hair is of two types:

1.Vellus hair 
Its found in the entire body- soft, fine, short, non pigmented or lightly pigmented.

2.Terminal hair
Its Coarse, long, dark, terminal hairs are the ones that respond to laser therapy.

They are present on scalp, underarms, eyebrow, beard, pubic area and chest.